Answer:
The 90% confidence interval is [tex] -0.3433< \mu_1 - \mu_2 < 2.1433[/tex]
Step-by-step explanation:
From the question we are told that
The sample mean for men is [tex]\= x_1 = 64.5 \ years[/tex]
The sample mean for women is [tex]\= x_2 = 63.6 \ years[/tex]
The sample size for men is [tex]n_1 = 35[/tex]
The sample size for women is [tex]n_2 = 39[/tex]
The standard deviation for men is [tex]s_1 = 3.0[/tex]
The standard deviation for women is [tex]s_2 = 3.5[/tex]
From the question we are told the confidence level is 90% , hence the level of significance is
[tex]\alpha = (100 - 90 ) \%[/tex]
=> [tex]\alpha = 0.10[/tex]
Generally from the normal distribution table the critical value of [tex]\frac{\alpha }{2}[/tex] is
[tex]Z_{\frac{\alpha }{2} } = 1.645 [/tex]
Generally the standard error is mathematically represented as
[tex]SE = \sqrt{\frac{s_1^2 }{n_1} + \frac{s_2^2}{n_2} }[/tex]
=> [tex]SE = \sqrt{\frac{3^2 }{35} + \frac{3.5^2}{39} }[/tex]
=> [tex]SE = 0.7558[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * SE[/tex]
=> [tex]E = 1.645 * 0.7558[/tex]
=> [tex]E = 1.2433[/tex]
Generally 90% confidence interval is mathematically represented as
[tex](\= x_1 - \= x_2) -E < \mu_1 - \mu_2 < (\= x_1 - \= x_2) -E [/tex]
=> [tex](64.5 - 63.6) -1.2433< \mu_1 - \mu_2 <(64.5 - 63.6) +1.2433[/tex]
=> [tex] -0.3433< \mu_1 - \mu_2 < 2.1433[/tex]
An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 5.6 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 160 engines and the mean pressure was 5.7 pounds/square inch. Assume the variance is known to be 0.25. A level of significance of 0.01 will be used. Make a decision to reject or fail to reject the null hypothesis.
Answer:
The decision rule is
Reject the null hypothesis
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 5.6 \ pounds/inch^2[/tex]
The sample size is n = 160
The sample mean is [tex]\= x = 5.7 \ pounds/ inch^2[/tex]
The variance is [tex]\sigma ^2 = 0.25[/tex]
The level of significance is [tex]\alpha = 0.01[/tex]
The null hypothesis is [tex]H_o : \mu = 5.6[/tex]
The alternative hypothesis is [tex]H_a : \mu > 5.6[/tex]
Generally the standard deviation is mathematically represented as
[tex]\sigma = \sqrt{\sigma ^2 }[/tex]
=> [tex]\sigma = \sqrt{0.25 }[/tex]
=> [tex]\sigma = 0.5[/tex]
Generally the test statistics is mathematically represented as
[tex]z = \frac{\= x - \mu }{ \frac{\sigma}{\sqrt{n} } }[/tex]
=> [tex]z = \frac{5.7 - 5.6 }{ \frac{0.5 }{\sqrt{ 160 } } }[/tex]
=> [tex]z = 2.53[/tex]
From the z table the area under the normal curve to the left corresponding to 2.53 is
[tex]p-value = P(Z > 2.53 ) =0.0057[/tex]
From the value obtained we see that the [tex]p-value < \alpha[/tex] hence
The decision rule is
Reject the null hypothesis
The conclusion is
There is sufficient evidence to conclude that the believe that the valve performs above the specifications is true
An airport limo service charges riders a fixed charge of $15 plus
$4.00 per mile. How many miles must a rider go to have an
average cost per mile of $4.60?
Given:
An airport limo service charges riders a fixed charge of $15 plus $4.00 per mile.
To find:
Distance in miles must a rider go to have an average cost per mile of $4.60.
Solution:
Let x be the number of miles the rider travel.
Total charges = Fixed charges + Variable charges
According to the question,
Fixed charges = $15
Variable charges = $4x
So, total charges
[tex]T=15+4x[/tex]
Divide the total charges by number of miles to get the cost per mile.
[tex]\text{Cost per mile}=\dfrac{15+4x}{x}[/tex]
Average cost per mile is $4.60.
[tex]4.60=\dfrac{15+4x}{x}[/tex]
[tex]4.60x=15+4x[/tex]
[tex]4.60x-4x=15[/tex]
[tex]0.60x=15[/tex]
Divide both sides by 0.60.
[tex]x=\dfrac{15}{0.60}[/tex]
[tex]x=25[/tex]
Therefore, the required number of miles is 25.
Juanita earns $36 for 3 hours of work. At that rate, how long would she have to work to earn $720?
Answer:
She has to work for 60hours in order to earn $720.
Step-by-step explanation:
Amount of money earned in 1hour=36÷3
=12$
Total time required=720÷12
=60hours
1. Line K is represented by the equation y =- 2/3x +4. Line Lis perpendicular to line K and
passes through the point (4,- 1). Determine the equation of line L.
Answer:b
Step-by-step explanation:
because i got i right
Help please this is my last question to my test need help don’t pass this up
Answer:
I dunno... I'm sorry I can't help
Step-by-step explanation:
Answer:
2z
Step-by-step explanation:
write the first 5 composite numbers?
Answer:
4, 6, 8, 9, 10, 12, 14, 15, 16
Step-by-step explanation:
"The first few composite numbers (sometimes called "composites" for short) are 4, 6, 8, 9, 10, 12, 14, 15, 16, ... (OEIS A002808), whose prime decompositions are summarized in the following table. Note that the number 1 is a special case which is considered to be neither composite nor prime."
hope this helps :)
There are 65 people coming to your party and each person will need one cup. How many packages of cups should you buy if one package contains 3 cups?
ANWSER:
STEP BY STEP EXAMPLE:
Answer: 22
Step-by-step explanation: 65 divided by 3 is 22
Answer:
21or22
Step-by-step explanation:
65/3
which of the equations below represents a line parallel to the x-axis?
a. x=5
b. y=1/x
c. y=x
d. y=5
Answer:
d. y=5
Step-by-step explanation:
The equation of a line parallel to the x-axis will always be in the form y=b, where b is the y-intercept (where on the y-axis the line crosses). So, for y=5, the line crosses the y-axis when y is equal to 5.
The equation of a line parallel to the y-axis will always be in the form x=d, where d is the x-intercept (where on the x-axis the line crosses). So, for option a, x=5, it is a vertical line that crosses the x-axis when x is equal to 5. It is therefore not parallel to the x-axis.
Option b gives an equation that isn't for a linear relation entirely.
Linear equations are typically given in the form y=mx+b, where m is the slope of the line and b is, again, the y-intercept. Option c presents the equation of y=x, and this can be rewritten as y=1x+0. In other words, the slope of the line is 1 and it crosses the y axis when y is equal to 0. Lines that are parallel to the x-axis will always have a slope of 0, so therefore, this line is not parallel to the x-axis.
I hope this helps!
where do i place the dots/arrows? will give brainliest!!!
Answer:
Step-by-step explanation:
first 95 x 60 (60 because there is 60 minutes in an hour) then multiply that number by 10 then start ploting the numbers up for example it goes 57,000 then multiply that by 2 and keep ploting.
if you can buy 3 loaves of bread for $5 how many loaves can you buy for $12
Answer:
You can buy 6 because it cost 2.50 for 1 loaf
Step-by-step explanation:
what is the domain of the function represented by the graph?
Answer:
option A is the answer
Step-by-step explanation:
............
A farmer wants to fence in a rectangular plot of land adjacent to the north wall of his barn. No fencing is needed along the barn, and the fencing along the west side of the plot is shared with a neighbor who will split the cost of that portion of the fence. If the fencing costs $14 per linear foot to install and the farmer is not willing to spend more than $7000, find the dimensions for the plot that would enclose the most area. (Enter the dimensions as a comma separated list.)
Answer:
Width = 166.7 ft
Length = 250 ft.
Step-by-step explanation:
From the diagram at the ATTACHMENT
Let us denote the the length of the rectangular area as "x" and
the width of the rectangular area as "y"
Since, cost of the fence on the western side is shared with a neighbor, we can say it is $7 per foot. Otherwise, it is $14 per foot. The northern length is not fenced.
From the question, we know that the cost is not to exceed $7000, therefore we can expressed it as
7y + 14x + 14y = 7000
14x + 21y = 7000
Divide through by 14, we have
(x + 1.5) = 500 ------------- eqn (*)
But the area of the fenced
= A = (x×y) -------------- eqn (**)
Substitute (*) into (**) we have
A = (500 - 1.5y)*y
= 500y - 1.5y²
In other to maximize the Area, we can find the differential of A
A'(y) = 500 - 3y
At A'(y) = 0.
500-3y= 0
3y=500
y= 166.67 ft
From eqn(*)
(x+ 1.5) = 500
x = 500 - 1.5y
500-1.5(166.67)
= 250ft
Therefore, the dimensions for the plot that would enclose the most area are
Width of 166.67 ft and Length = 250 ft.
When multiplying, the answer is negative when you:
A: multiply a positive (+) times a negative (-)
B: multiply a negative (-) times a negative (-)
C: multiply a positive (+) times a positive (+)
Step-by-step explanation:
b: multiplying a negative (-) by a negative (-)
The table on the left is that of a linear function, and the one on the right is that of an exponential function.
Can you tell which function has the higher rate of growth? How?
A)
There is not enough information to make a conclusion.
B)
The linear function is growing faster, because at x = 3 the y-value of the
linear function is larger.
C)
The exponential function is growing faster, because at x = 0 the y-value of
the exponential function is larger.
D)
The exponential function is growing faster, because it grows by a factor
that is multiplied by the previous y-value instead of being added like the
linear function.
Answer:
The answer is option D) The exponential function is growing faster, because it grows by a factor that is multiplied by the previous y-value instead of being added like the linear function.
Step-by-step explanation:
We can easily that by evaluating both functions at x = 10
Linear
f(x) = 7*10 = 70
Exponential
f(x) = 2^(10) = 1024
Using the binomial theorem, expand the expression (4 + y) to the power of 4
Answer:
When raised to the power of 4, the binomial (4 + y) expands to:
[tex]y^4 + 16y^3 + 96y^2 + 256y + 256[/tex]
Step-by-step explanation:
[tex](4 + y)^4 \\= (y^2 + 8y + 16)^2\\= y^4 + 8y^3 + 16y^2 + 8y^3 + 64y^2 + 128y + 16y^2 + 128y + 256\\= y^4 + 16y^3 + 96y^2 + 256y + 256[/tex]
Which graph has x-intercept (-5,0) and y-intercept (0,-2)?
The top one is x-intercept, and the bottem one is y-intercept. Also the gray boxes are your answer
The graph of the x-intercept at x = -5 and y-intercept at y = -2 is given below.
What is an equation of a line?The equation of a line is given by:
y = mx + c
where m is the slope of the line and c is the y-intercept.
Example:
The slope of the line y = 2x + 3 is 2.
The slope of a line that passes through (1, 2) and (2, 3) is 1.
We have,
x-intercept = (-5, 0)
This means,
It is a vertical line at x = -5.
y-intercept = (0, -2)
This means,
It is a horizontal line at y = -2.
Thus,
The graph is given below.
Learn more about equation of a line here:
https://brainly.com/question/23087740
#SPJ2
Please help these are two different questions !
Answer:
120 Girls
Step-by-step explanation:
First, you have to combine the dark shade girls and the light shade girls together to get 7.
Then, you should divide 210 by 7, to get 30
Finally, using 30 as your multiplier,
you go and multiply 30 x 4 to get 120 girls :D
What is 1 15/16 divede by 7/8 in fraction form
Answer:
2 13/16
Step-by-step explanation:
1 15
16
+
7
8
= (1 + 0) + (
15
16
+
7
8
)
= 1 +
15
16
+
7 × 2
8 × 2
= 1 +
15
16
+
14
16
= 1 +
15 + 14
16
= 1 +
29
16
= 1 +
1 13
16
=
2 13
16
WILL MARK BRANLIEST TO THE CORRECT ANSWER!
You decide to invest $250 in an account that yields a return of approximately 4% each year. What is the value of you investment after 15 years if you make no further deposits or withdrawals?
Answer:
$450.24
Step-by-step explanation:
According to my quiz...
Why is it a good idea to check to see if your answer is reasonable?
a. if your answer is reasonable, you have
b. if you understand the problem, you will not need to check your answer.
c. you just need to solve for the varible
d. to get the correct answer, you will need to need to check your answer draw a picture
Please select the best answer from the choices provided.
Answer:
D number option is the correct answer
Answer:
A. if your answer is reasonable, you have probably done the problem correctly
Step-by-step explanation:
find 59.2% of 250...................................
Answer:
148
Step-by-step explanation:
just searched it up good luck sorry if its wrong
Find the value of x.
Group of answer choices
25
40
65
115
Answer:
40
Step-by-step explanation
x=40 because if you time these in like this:
3(40)-10= 110
40+15=55
If you user 65 it'll be wrong because:
3(65)-10=185
And the whole thing is only 180 :]
Chuck made $13.90 per hour, gets a 12% raise, and works 40 hours per week.
Answer:
40 times 9 equals 299
Step-by-step explanation:
At her birthday party, marcie's guests ate 2/3 of her birthday cake and her family ate 1/4 of the cake. How much cake was left after her party?
Answer:
1/12
Step-by-step explanation:
So you start with an equation. 2/3 plus 1/4= ?.
Step 1: Find a common donominator.
Count by each number until they meat up.
3 6 9 12
4 8 12
Step 2: Multiply.
Basically, make sure that if you do something to the bottom you do the same to the top. You have
[tex]\frac{2}{3}[/tex] = [tex]\frac{?}{12}[/tex]. 3 times 4 is 12. 2 times 4 is 8. Your new fraction is [tex]\frac{8}{12}[/tex].
[tex]\frac{1}{4}[/tex] = [tex]\frac{?}{12}[/tex]. 4 times 3 is 12. 1 times 3 is 3. Your new fraction is [tex]\frac{3}{12}[/tex].
Step 3: Just Add!
[tex]\frac{8}{12} + \frac{3}{12}= \frac{11}{12}[/tex]
Step 4: Answer the question! The question asks "How much cake is left. You know that a whole cake is [tex]\frac{12}{12}[/tex]. So, [tex]\frac{12}{12} -\frac{11}{12} = \frac{1}{12}[/tex]
unit rate of 122 and 10 please
Write the data from greatest to least: 0.8, 0.79, 0.08, 0.81, 0.09, 0.9, 0.89
Answer:
0.9, 0.89, 0.81, 0.8, 0.79, 0.09, 0.08
Step-by-step explanation:
Answer: 0.09 , 0.89 , 0.81, 0.08, 0.79 , 0.9, 0.8
Step-by-step explanation:
First find the greatest
0.09, 0.89,0.81, 0.08, 0,79
Then the least
0.9 .0.8
Now put it all together
0.09, 0.89. 0.81 , 0.08, 0.79 , 0.9, and lastly 0.8
Help!! Im stuck on this!
(2x + 3) + (3x + 5)
(8x^2 - 3x +3) + (2x^2 -4x +6)
3 * (2x - 6)
2x * (5x + 11)
*****
(2x + 8) - (4y + 1)
-5x * (3x^2 - 2x - 1)
What do we need to watch for in problems like this?
Answer:
when doing questions like these you need to do pemdas and do it in order
Step-by-step explanation:
p- parenthesis
e- exponents
m- multipication
d- division
a- adding
s- subtracting
janet can read 2.95 pages of a book in a minute if she reads for 4.7 minutes how much would she have read
Answer:
Janet reads 13.865 pages in 4.7 minutes.
Step-by-step explanation:
Given that Janet can read 2.95 pages of a book in a minute.
unit rate = 2.95 pages/per minuteAs she reads for 4.7 minutes.
We just need to multiply 4.7 minutes with 2.95 to determine total pages she would read in 4.7 minutes.
i.e.
4.7 × 2.95 = 13.865 pages
Therefore, Janet reads 13.865 pages in 4.7 minutes.
The band director of Eagle Rock High School asks her students to have a carwash as a fundraiser. They are going to charge $7.50 per car. The graph that represents the situation is shown below. Which of the following statements about the graph are true? Select all that apply. o The graph represents a function since every input value corresponds to exactly one output value. o The graph has an x-intercept. o The graph has a y-intercept. o The y-intercept represents the amount of money raised by the carwash. o The amount of money in the band fundraiser account represents the input values. o The number of cars washed relates to the amount of money in the band fundraiser account.
Answer:
The y-intercept represents the amount of money raised by the carwash.
The graph has a y-intercept
Step-by-step explanation:
Most reasonable, and not only that it's true bc it's shown on the graph label. :)
Esteban has $100 in bills. He has 22 bills total and each of them is either a $10 bill or a $2 bill. How many $10 bills does Esteban have?