The random variable X represents the length of each engineering conference, and is measured in days.
The normal distribution should be used for this problem, as the underlying population is normal. The normal distribution is a continuous probability distribution that is characterized by a symmetric bell-shaped curve. It is a useful model for events that follow a normal or Gaussian pattern, such as the lengths of engineering conferences.
c. i. The 95% confidence interval for the population mean length of engineering conferences is (3.38, 4.50) days.
ii. The graph of the 95% confidence interval for the population mean length of engineering conferences is shown below.
iii. The error bound for the 95% confidence interval is 0.77 days. This can be calculated using the formula: Error Bound = 1.96*(standard deviation/√sample size). In this case, the error bound is calculated as: 1.96 * (1.28/√84) = 0.77.
Learn more about normal distribution here:
https://brainly.com/question/29509087
#SPJ4
Step 2 - Fill in the missing number: A vertical line and horizontal line combine to make a L shape. There is one row of entries in the shape including 1, negative 3, negative 10, 24. On the outside to the left of the L shape is 2 and to the outside below 1 is a. a =
The synthetic division's representation of the dividend is 2x3 + 10x2 + x + 5.
Given that
An L shape is created when two lines intersect vertically and horizontally.
The shape has entries in two rows.
Entries in row 1 are 2, 10, 1, and 5.
Blank, -10, and 0 are the entries in row 2.
A simplified method of dividing a polynomial with another polynomial equation of degree one is known as synthetic division.
On the exterior, to the left of the form, is entry number 5.
The entry stands for the divisor's zero.
If the variable is x, then this entry to the variable is;
2x³+10x²+x+5
The dividend is thus represented by synthetic division as
2x³+10x²+x+5
The Question is incomplete And complete question is given below!!
What dividend is represented by the synthetic division below? A vertical line and horizontal line combine to make a L shape. There are two rows of entries within the shape. Row 1 has entries 2, 10, 1, 5. Row 2 has entries blank, negative 10, 0, negative 5. Entry negative 5 is on the outside to the left of the shape, and a third row of entries is outside and below the shape. Row 3 has entries 2, 0, 1, 0. Negative 10 x squared minus 5 2 x cubed 10 x squared x 5 2 x squared 1 2 x cubed x.
Learn more about Synthetic division here
https://brainly.com/question/27979968
#SPJ1
Answer:
The answer on Edge is A= 1
Step-by-step explanation:
Surface=
Area=
Help please thanks
Surface area of the rectangular solid = 416 in.².
Volume = 480 in.³.
What is the Surface Area and Volume of a Rectangular Solid?Surface area = 2(wl+hl+hw)
Volume = (length)(width)(height).
Given the following:
Length (l) = 12 in.
Width (w) = 10 in.
Height (h) = 4 in.
Surface area = 2(wl+hl+hw) = =2·(10·12+4·12+4·10) = 416 in.².
Volume = (12)(10)(4) = 480 in.³.
Learn more about the surface area of rectangular solid on:
https://brainly.com/question/1310421
#SPJ1
Bd=16 and ac is the perpendicular bisector of bd. 2x-14 37-x d 2y-2 3 y=[?] enter
The value of y from the given expression is 5
Perpendicular Bisector
Given:
BD = 16
BC = 2y - 2
CD = y + 3
Since AC is a perpendicular bisector of BD:
BC = CD
2y - 2 = y + 3
2y - y = 3 + 2
y = 5
Hence, the value of y from the given expression is 5
Learn more on perpendicular bisector here: https://brainly.com/question/11006922
#SPJ1
Bob and Carol are teenagers. Bob is two years older than Carol. If the digits of Carol's age are reversed, the new number would be three times as large as Bob's age. Find Bob's age.
Bob is 2 years older than Carol and the reverse of Carol's age is 3 times Bob's age, which makes Bob's to be 17 years.
How can Bob's age be calculated?Let 1B represent Bob's age and let 1C represent Carol's age, we can write the following equations;
1B = 1C + 2Reversing Carol's age gives;
C1 = 3 × 1BThe multiples of 3 that have the form X1 have 7 as the rightmost number.
Given that 1B is a teenager, we have;
When;
1B = 171C = 17 - 2 = 15The reverse of Carol's age is therefore;
C1 = 51 = 3 × 17Therefore, from the given description, Bob's age 1B = 17 years
Bob is 17 years oldLearn more about writing equations here:
https://brainly.com/question/18831805
#SPJ1
Use the graph that shows the solution to f(x)=g(x).
f(x)=1/x−2
g(x)=x−2
What is the solution to f(x)=g(x)?
Select each correct answer.
−1
1
2
3
The solution to the system of equations is given as follows:
x = 1 and x = 3.
What is a system of equations?A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the two equations are:
[tex]\frac{1}{x - 2} = x - 2[/tex]
Applying cross multiplication:
(x - 2)(x - 2) = 1
x² - 4x + 4 = 1
x² - 4x + 3 = 0
(x - 1)(x - 3) = 0
Hence the solutions are:
x - 1 = 0 -> x = 1.x - 3 = 0 -> x = 3.More can be learned about a system of equations at https://brainly.com/question/24342899
#SPJ1
What are the roots of the polynomial equation? –3, –2, 3 –3, 2 18, 32 18, 32, 66
The root of the polynomial function x^3 - 2x^2 + 5x - 6 = -4x^2 + 14x + 12 is -3, -2 and 3
How to determine the roots of the equation?The graph that completes the question is added as an attachment
The polynomial function is given as:
x^3 - 2x^2 + 5x - 6 = -4x^2 + 14x + 12
From the attached graph, we have the following highlight:
The curves of both equations intersect at
x = -3, x = -2 and x = 3
This means that the root of the polynomial function is -3, -2 and 3
Hence, the root of the polynomial function x^3 - 2x^2 + 5x - 6 = -4x^2 + 14x + 12 is -3, -2 and 3
Read more about polynomial function at
https://brainly.com/question/10989434
#SPJ1
Complete question
Carlos graphed the system of equations that can be used to solve x^3 - 2x^2 + 5x - 6 = -4x^2 + 14x + 12
What are the roots of the polynomial equation?
A) –3, –2, 3
B) –3, 2
C) 18, 32
D) 18, 32, 66
The radius of a sphere-shaped balloon increases at a rate of 2 centimeters (cm) per second. If the surface area of the completely inflated balloon is 784π cm2, how long will it take for the balloon to fully inflate?
Considering the surface area of the spherical ballon, it will take 7 seconds for the the balloon to fully inflate.
What is the surface area of a sphere?The surface area of a sphere of radius r is given by:
[tex]S = 4\pi r^2[/tex]
In this problem, the surface area is of [tex]784\pi[/tex] cm², hence the radius in cm is found as follows:
[tex]784\pi = 4\pi r^2[/tex]
[tex]4r^2 = 784[/tex]
[tex]r^2 = \frac{784}{4}[/tex]
[tex]r^2 = 196[/tex]
[tex]r = \sqrt{196}[/tex]
r = 14 cm.
The radius start at 0 cm, inflating at a rate of 2 cm/s, hence it will take 7 seconds for the the balloon to fully inflate, as 14 cm/(2 cm/s) = 7 s.
More can be learned about the surface area of a sphere at https://brainly.com/question/21207980
#SPJ1
please provide the answer?
Using the given table:
a) the average rate of change is 32.5 jobs/year.
b) the average rate of change is 12.5 jobs/year.
How to find the average rate of change?
For a function f(x), the average rate of change on an interval [a, b] is:
[tex]\frac{f(b) - f(a)}{b - a}[/tex]
a) The average rate of change between 1997 and 1999 is:
[tex]A = \frac{695 - 630}{1999 - 1997} = 32.5[/tex]
So the average rate of change is 32.5 jobs/year.
b) Now the interval is 1999 to 2001.
The rate this time is:
[tex]A ' = \frac{720 - 695}{2001 - 1999} = 12.5[/tex]
So the average rate of change is 12.5 jobs/year.
If you want to learn more about average rates of change:
https://brainly.com/question/8728504
#SPJ1
The sum of 3 consecutive integers is 2190. what is the value of the smallest integer?
Answer:
3x+2=2190
3x=2190-2
3x=2188
x=2188÷3
x=729
How do you know that ABC is similar to BDC? Explain your answer.
Answer: No
Step-by-step explanation:
There is only one pair of congruent angles that can be determined, but to prove triangles similar, there needs to be two pairs of congruent angles.
What is the solution to the system of equations? (–21, 9) (9, –21) (–1, 9) (9, –1)
The solution to the system of equations is the point ( -1, 9 ).
What is the solution to a system of linear equations?
If you have a system of equations that contains two equations with the same two unknown variables, then the solution to that system is the ordered pair that makes both equations true at the same time.
The system of equations
y = -3x + 6 ...................(1)
y = 9 .................(2)
Substitute equation (2) in equation
9 = -3x + 6
subtract both sides
9 - 6 = -3x + 6 - 6
3 = -3x
Divide by -3 both sides
x = -1
the solution is the point ( -1, 9 )
Therefore,the solution to the system of equations is the point ( -1, 9 ).
Learn more about the solution to the system of linear equation
brainly.com/question/13631560
#SPJ4
The complete question is -
Y = –3x + 6 y = 9 what is the solution to the system of equations? (–21, 9) (9, –21) (–1, 9) (9, –1)
Answer:
c
Step-by-step explanation:
What is the solution to the system of equations?
(–21, 9)
(9, –21)
(–1, 9)
(9, –1)
PLEASE HELP WILL GIVE YOU ALOT OF POINTS
The blades of a windmill turn on an axis that is 35 feet above the ground. The blades are 10 feet long and complete two rotations every minute. Which of the following equations can be used to model h, the height in feet of the end of one blade, as a function of time, t, in seconds
The correct option is (c) h = 10sin(π15t)+35.
The equations can be used to model h, the height in feet of the end of one blade, as a function of time, t, in seconds is h = 10sin(π15t)+35.
How do windmills rotate?The blades of a turbine, which resemble propellers and function much like an airplane wing, capture the wind's energy.
A pocket of low-pressure air develops on one side of the blade when the wind blows. The blade is subsequently drawn toward the low-pressure air pocket, which turns the rotor.
Calculation for the equation of the model height-
Let's now review each choice individually and select the best one.
The blade is horizontal at time t = 0. As a result, h = 35 at t = 0 is valid for all of the possibilities in this situation.
They accomplish two spins in a minute. The blades will so complete one rotation in 30 seconds. and they will complete a quarter rotation in 15/2 seconds. Because of this, the blade will be vertically up from time t = 0 to t = 15/2. Its height in this instance should be 35 + 10 = 45 ft. Let's now examine the available possibilities.
If we put t=15/2 in the options
Option (a) gives h = 25
Option (b) gives h = -10sin(15/2) + 35
Option (c) gives h = 45
Option (d) gives h = 10sin(15/2) + 35
Therefore, the correct equation is given in option c.
To know more about windmill, here
https://brainly.com/question/2031508
#SPJ4
The complete question is -
The blades of a windmill turn on an axis that is 35 feet above the ground. The blades are 10 feet long and complete two rotations every minute. Which of the following equations can be used to model h, the height in feet of the end of one blade, as a function of time, t, in seconds? Assume that the blade is pointing to the right, parallel to the ground at t = 0 seconds, and that the windmill turns counterclockwise at a constant rate.
a) h = −10sin(π15t)+35
b) h = −10sin(πt)+35
c) h = 10sin(π15t)+35
d) h = 10sin(πt)+35
PLEASE HELP IM STUCK
Answer:
y =- [tex]\frac{1}{4}[/tex]x - 1
Step-by-step explanation:
You are asked to give the equation of the line in slope intercept form, y = mx + b, where m represents the slope and b represents the y-intercept.
Y-intercept is the point where the graph intersects the y-axis at point (b, 0). The graph seems to cross the y-axis at (-1, 0), so the b value is -1.
Slope is rise over run. Looking at the graph, it goes down 1 unit every 4 units to the right, so the slope is -1/4.
Answer:
Below in bold.
Step-by-step explanation:
The slope is -1/4 and y-intercept is -1
y = -1/4x - 1
-499" is to the __________ of "-500" on a number line
Answer: right
Step-by-step explanation:
[tex]-499 > -500[/tex], and larger numbers are to the right of numbers smaller than them on the number line.
Which of the following functions are solutions of the differential equation y'' + y = sin(x)? (Select all that apply.) y = − 1 2 x cos(x)
The function that is the solution of the differential y" + y = sin(x) is: y(x) = -1/2(x cos x)
What is a function?A function is an expression, rule, or law in mathematics that describes a connection between one factor (the independent variable) and another variable (the dependent variable).
What is the proof of the above function?Take a look at the the following differential equation:
y" + y = sin (x)
The auxiiliary equation is
m² + 1 = 0
m² + 1-1 = -1
m² + 0 = -1
m² = -1
m = ±√-1
m = ±i
So, the complimentary function is yₐ (x) = c₁ cos x + c₂ sin x
Let the particular integral be:
yₙ (x) = A cos x + B sin x
yₙ '(x) = - A sin x + B cos x
yₙ ''(x) = - A cos x + B cos x
yₙ ''(x) = - (A cos x + B cos x)
After we have substituted yₙ (x); and yₙ''(x) in the given differential equation
y'' + y = sin (x)
= - (A cos x + B cos x) + (A cos x + B cos x) = sin(x)
0 = sin (x)
If we take the particular integral to be:
yₙ (x) = x(A cos x + B cos x)
yₙ '(x) = x(-A sin x + B cos x) + A cos x + B cos x
yₙ ''(x) = x(-A cos x - B sin x) - A sin x + B cos x + -A sin x + B cos x
Substitute yₙ (x), yₙ''(x) into the stated differential equation
y'' + y = sin (x)
x (-Acosx - Bsin x) - Asinx + Bcosx + (-Asinx + Bcosx) - x (Acosx + Bsin x) = sin (x)
-Axcosx - Bxsin x - Asinx + Bcosx -Asinx + Bcosx - Axcosx + Bxsin x = sin (x)
-2Asinx + 2Bcosx = sin(x)
Compare the coefficients of like terms on both sides of the equation
-2A = 1, B = 0
A = -1/2, B = 0
Substitute A = -1/2, B =0 into the assumed solution.
yₙ(x) = x((-1/2)cosx + (0) sinx)
= -1/2xcosx +0
= -(1/2)xcosx
Now, the general solution for the given differential equation is:
y(x) = yₓ(x) +yₙ (x)
y (x) - c₁cosx + c₂sin x -1/2x cosx
Hence, the solution is:
y(x) = -1/2xcosx
Learn more about function at;
https://brainly.com/question/25638609
#SPJ1
Full Question:
Which of the following functions are solutions of the differential equation y'' + y = sin x? (Select all that apply.)
A) y = 1 2 x sin x
B) y = cos x
C) y = x sin x − 5x cos x
D) y = − 1 /2 x cos x
E) y = sin x
On a balance scale, $3$ green balls balance $6$ blue balls, $2$ yellow balls balance $5$ blue balls, and $6$ blue balls balance $4$ white balls. How many blue balls are needed to balance $4$ green, $2$ yellow and $2$ white balls
The number of blue balls that are needed to balance four green, two yellow and two white balls is 16 blue balls.
Numbers of blue balls neededGreen(g)
Blue (b)
Yellow (y)
White (w)
First step is to formula an equation
3g=6b
g=2b
2y=5b
y=5/2b
4w=6b
w=3/2b
Second step is to substitute
4g+2y+2w
=4(2b)+2(5/2b)+2(3/2b)
=8b+5b+3b
=16b
Therefore 16 blue balls are needed.
Learn more about Numbers of blue balls needed here:https://brainly.com/question/27895170
#SPJ1
use the intermediate value theorem to prove that there is a positive number c such that c2 = 2.
So lets try to prove it,
So let's consider the function f(x) = x^2.
Since f(x) is a polynomial, then it is continuous on the interval (- infinity, + infinity).
Using the Intermediate Value Theorem,
it would be enough to show that at some point a f(x) is less than 2 and at some point b f(x) is greater than 2. For example, let a = 0 and b = 3.
Therefore, f(0) = 0, which is less than 2, and f(3) = 9, which is greater than 2. Applying IVT to f(x) = x^2 on the interval [0,3}.
Learn more about Intermediate Value Theorem on:
https://brainly.com/question/11377865
#SPJ4
Need it solved correctly for khan academy
The tiger population loses 3/5 of its size every 2.94 decades
Rate of change using differential calculus
The given equation is:
[tex]N(t)=710(\frac{8}{125} )^t[/tex]
Find the derivative of the given function
[tex]\frac{dN}{dt} =710(0.064)^tln(0.064)\\\\\frac{dN}{dt} =-1951.7(0.064)^t[/tex]
When the tiger loses 3/5 of its population
dN/dt = 3/5
Solve for t
[tex]\frac{3}{5} =-1951.7(0.064)^t\\\\-0.0003=(0.064)^t[/tex]
Take the natural logarithm of both sides
[tex]ln(-0.0003)=t(ln0.064)\\\\-8.087=-2.75t\\\\t=\frac{-8.087}{-2.75} \\\\t=2.94[/tex]
The tiger population loses 3/5 of its size every 2.94 decades
Learn more on rate of change using calculus here: https://brainly.com/question/96116
#SPJ1
What is the distance between the points (22,27) and (2,-10)
Answer:
42.1
Step-by-step explanation:
The formula to calculate distance is √[(x₂ - x₁)² + (y₂ - y₁)²]. Using (22,27) as our x1 and y1, and (2,-10) as our x2 and y2.
Therefore our formula is √[(2 - 22)² + (-10 - 27)²].
(2 - 22)² = 400
(-10 - 27)² = 1369
(Make sure for both of these you put the negative number in parenthesis and the exponent outside them, if you are using a calculator of some sort)
Then we add and square root
√[400 + 1369] = 42.0594816896
The distance between the points (22,27) and (2,-10) is 42.1 units
How to determine the distance between the points?The coordinates of the points are (22,27) and (2,-10)
The distance is calculated as:
[tex]d = \sqrt{(x_2 -x_1)^2 + (y_2 -y_1)^2[/tex]
So, we have:
[tex]d = \sqrt{(22 -2)^2 + (27 +10)^2[/tex]
Evaluate
[tex]d = \sqrt{1769[/tex]
Take the square root
d = 42.1
Hence, the distance between the points (22,27) and (2,-10) is 42.1 units
Read more about distance at:
https://brainly.com/question/7243416
#SPJ1
Determine the equation of the parabola graphed below. Note: be sure to consider the negative sign already present in the template equation when entering your answer. A parabola is plotted, concave up, with vertex located at coordinates negative three and negative four.
The equation of the graphed parabola is y=a[tex](x+3)^{2}[/tex]-4.
Given that parabola is plotted, concave up , with vertex located at coordinates (-3,-4).
We are required to find the equation of the graphed parabola.
The equation of a quadratic function of vertex (h,k) is given by:
y=a[tex](x-h)^{2}[/tex]+k
In the above equation a is the leading coefficient.
We have been given point (-3,-4).
We have to just put the value of h=-3 and k=-4 and the required equation will be as under:
y=a[tex](x+3)^{2}[/tex]-4
Hence the equation of the parabola which is plotted, concave up, with vertex located at coordinates (-3,-4) is y=a[tex](x+3)^{2}[/tex]-4.
Learn more about parabola at https://brainly.com/question/64712
#SPJ4
Can someone help me? Just complete these 2 proofs (geometry), ASAP!!!!
Question 4
1) [tex]\overline{AC} \cong \overline{AE}, \overline{AB} \cong \overline{AD}[/tex] (given)
2) [tex]\angle A \cong \angle A[/tex] (reflexive property)
3) [tex]\triangle ABC \cong \triangle ADC[/tex] (SAS)
Question 5
3) [tex]\angle ABC \cong \angle DCB[/tex] (all right angles are congruent)
4) [tex]\overline{AC} \cong \overline{AC}[/tex] (reflexive property)
5) [tex]\triangle ABC \cong \triangle DCB[/tex] (AAS)
give the volume and surface area of the sphere shown
Answer:
V≈3053.63
A≈1017.88
Step-by-step explanation:
V=[tex]\frac{4}{3}[/tex]π [tex]r^{3}[/tex]=[tex]\frac{4}{3}[/tex]·π·[tex]9^{3}[/tex] ≈3053.62806
A=4π[tex]r^{2}[/tex]=4·π·[tex]9^{2}[/tex] ≈1017.87602
ASSIGNMENT
Evaluate -
[tex]\sf \: \displaystyle\int_{ - 1}^{25}\sf {e}^{x - [x]} [/tex]
- Need help!
Answer:
26
Explanation:
[tex]\int\limits^{25}_{-1} {e^{x-[x]}} \, dx[/tex]
simplify
[tex]\int\limits^{25}_{-1} {e^{0} \, dx[/tex]
any variable to the power 0 is 1
[tex]\int\limits^{25}_{-1} 1 \, dx[/tex]
integrating 1 gives x
[tex]\left[ \:x \: \right]^{25}_{-1}[/tex]
apply limits
[tex]25 - (-1)[/tex]
add terms
[tex]26[/tex]
[tex]\\ \rm\hookrightarrow \displaystyle\int\limits_{-1}^{25}e^{x-[x]}dx[/tex]
[x] is x if x is a real number[tex]\\ \rm\hookrightarrow \displaystyle\int\limits_{-1}^{25}e^{x-x}dx[/tex]
[tex]\\ \rm\hookrightarrow \displaystyle\int\limits_{-1}^{25}e^0dx[/tex]
e⁰=1[tex]\\ \rm\hookrightarrow \displaystyle\int\limits_{-1}^{25}dx[/tex]
[tex]\\ \rm\hookrightarrow \left[x\right]_{-1}^{25}[/tex]
[tex]\\ \rm\hookrightarrow 25-(-1)[/tex]
[tex]\\ \rm\hookrightarrow 25+1[/tex]
[tex]\\ \rm\hookrightarrow 26[/tex]
If is any positive two-digit integer, what is the greatest positive integer that must be a factor of
Answer:
23
Step-by-step explanation:
small brain
which of the following would be a good name for the function that takes the length of a race and returns the time needed to complete it?
A. time(length)
B.length(time)
C.cost(time)
D. time(race)
The answer choice which best fits the function described in the task content is; Choice A; time(length).
Which would be a good name for the function?It follows from the task content that the function takes the length of a race and returns the time needed to complete it.
On this note, it follows that the time taken is a function of the length of the race.
Hence, the appropriate name of the function is; Choice A.
Read more functions;
https://brainly.com/question/17043948
#SPJ1
Sample response: there is a common ratio of 2/3 between the height of the ball at each bounce. so, the bounce heights form a geometric sequence: 27, 18, 12. two-thirds of 12 is 8, so on the fourth bounce, the ball will reach a height of 8 feet. what did you include in your response? check all that apply. there is a common ratio between bounce heights. multiply 12 by 2/3. the height on the fourth bounce is 8 feet.
Answer:
Step-by-step explanation:
A Geometric sequence can be used:
To Model this sequence you need to use this formula
A (subscript n) = Ar(n-1)
a = value of the first term
n = the # of the term you want to find (For example, if you want to find the term number 3, it is 12)
r = the common ratio, this is obtained by dividing the second term in the sequence by the first.
So the value of r is = 2/3 because 27 times 2/3 = 18 which is the second term
n = 4 since you want to find the 4th term in the sequence
Plug it in and the results are
4th term = 27(2/3)^(4-1) = 8
The answer is 8
Find the maximum of the objective
function, f, subject to the constraints
f = 4x + 3y
Maximum value = 880/3.
Maximizing the objective function in the LP model means that the value occurs in an acceptable set of decisions. Linear programming refers to selecting the best alternative from the available alternatives that can represent the objective and constraint functions as linear mathematical functions.
As mentioned above, the equation is an example of a constraint. You can use this to think about what it means to solve equations and inequalities. For example, solving 3x + 4 = 10 yields x = 2. This is an easy way to express the same constraints.
Learn more about constraints here: https://brainly.com/question/8729359
#SPJ4
A sequence is defined by the recursive function f(n + 1) =1/3 f(n). if f(3) 9= , what is f(1)
Answer:
f(1) = 81
Step-by-step explanation:
f(n + 1) = 1/3 f(n)
⇔ f(n) = 3 × f(n + 1)
……………………………
if f(3) = 9 ⇒ f(2) = 3 × f(3) = 3 × 9 = 27
Then
f(1) = 3 × f(2) = 3 × 27 = 81
The reference angle for is, which has a terminal point of (2).
What is the terminal point of ?
(-²)
(-4/2, 4/2)
○ B. (2,-²)
(-2/²2,-4/2)
OA
A.
O C.
○ D. (22)
Answer: C
Step-by-step explanation:
[tex]\frac{5\pi}{4}[/tex] is in the third quadrant, so both x and y are negative.
Therefore, the only possible answer is C.