The manager of an online shop wants to determine whether the mean length of calling time of its customers is significantly less than 9 minutes. A random sample of 28 customers was taken. The average length of calling time in the sample was 8.1 minutes with a standard deviation of 2.9 minutes. At a 0.05 level of significance, it can be concluded that the mean of the population is:

Answers

Answer 1

Answer:

Step-by-step explanation:


Related Questions

a person invests 6500 dollars in a bank. the bank pays 6.75% interest compounded semi-annually. to the nearest tenth of a year, how long must the person leave the money in the bank until it reaches 15700 dollars?
A = P(1+r/n)^nt

Answers

Answer:

t=13.28382 ≈ 13.3 years

It takes 13.3 years to amount $15700 from the principal $6500.

Given that, a person invests 6500 dollars in a bank. the bank pays 6.75% interest compounded semi-annually.

What is the compound interest?

Compound interest is the interest on savings calculated on both the initial principal and the accumulated interest from previous periods.

The formula used to find the compound interest = A = P(1+r/n)^nt

Now, 15700 =6500(1+6.75/2×100)^2t

⇒ 15700/6500=(1+6.75/200)^2t

⇒ 15700/6500=1.03375^2t

⇒ 2.415=1.03375^2t

Take the logarithm of both sides of the equation to remove the variable from the exponent.

Exact Form:

t=ln(2.415)/2ln(1.03375)

Decimal Form:

t=13.28141707

≈ 13.3 years

Therefore, it takes 13.3 years to amount $15700 from the principal $6500.

To learn more about the compound interest visit:

https://brainly.com/question/14295570.

#SPJ2

The admission fee at a local zoo is $1.50 for children and $4.00 for adults. On a certain day, 1,900 people enter the zoo and $5,600.00 is collected.

Answers

What are we trying to find? I might be more help if I know what we’re trying to find!

The expression (x^3) (x12) is equivalent to x^n. What is the value of n?

3 and n are exponents

Answers

Answer:

Step-by-step explanation:

(x^3) (12x)

(x^4)(12)

12x^4

We can really find the exponent without knowing what x is equal to but I hope this helps

Fide the volume and round to the nearest tenth . Please help I will give you brainless

Answers

Answer:

46

Step-by-step explanation:

Answer:

4.18 inch^3

Step-by-step explanation:

use the sphere volume formula :

V = (4/3)*pi*r^3

the radius of this sphere is 2/2 = 1 ( diameter / 2)

plugging in the values :

V = (4/3)*3.1415*1^3 = 4.18

Kelly has some savings. After mowing lawns Saturday, she added $70 to her savings. How much money has Kelly saved?

Answers

Answer:

70

Step-by-step explanation:

saveings +70 the money she added to the money he or she saved

Pretty sure it’s $70

A system has two components: A and B. The operating times until failure of the two components are independent and exponentially distributed random variables with parameter 2 for component A, and parameter 3 for component B. The system fails at the first component failure.
(a) - Read section 1.5.2 in the textbook.
(b) - What is the mean time to failure for component A and for component B

Answers

Answer:

[tex]E(x) = \frac{1}{2}[/tex] -- Component A

[tex]E(x) = \frac{1}{3}[/tex] -- Component B

Step-by-step explanation:

Given

Distribution = Exponential

[tex]\lambda = 2[/tex] --- Component A

[tex]\lambda = 3[/tex] --- Component B

Solving (a): The mean time of A

The mean of an exponential distribution is:

[tex]E(x) = \frac{1}{\lambda}[/tex]

We have:

[tex]\lambda = 2[/tex] --- Component A

[tex]E(x) = \frac{1}{2}[/tex]

Solving (b): The mean time of B

The mean of an exponential distribution is:

[tex]E(x) = \frac{1}{\lambda}[/tex]

We have:

[tex]\lambda = 3[/tex] --- Component B

[tex]E(x) = \frac{1}{3}[/tex]

(x+6)/(x+1)=6/2
Solving proportions

Answers

Answer:

[tex]x = \frac{3}{2} [/tex]

Step-by-step explanation:

[tex] \frac{x + 6}{x + 1} = \frac{6}{2} [/tex]

[tex] \frac{6}{2} = 3[/tex]

so, the solution of the equation will be as follows:

[tex] \frac{x + 6}{x + 1} = 3[/tex]

3(x+1) = x + 6

3x + 3 = x + 6

3x - x = 6 - 3

[tex]x = \frac{3}{2} [/tex]

so, the answer will be x = 3/2

Christa and James both walk from their houses to the bus stop every morning. Christa walks 1.9 kilometers further, and together they walk 4.1 kilometers.

If James walks a distance of d kilometers find the value of d.​

Answers

Answer:

James walks 2.2 kilometers it is because 4.1-1.9=2.2

Step-by-step explanation:

and to check u can add 2.2 in 1.9 ko get 4.1 so james walked 2.2 distance kilometers from his house.

Answer:

Step-by-step explanation:

d + (d+1.9) = 4.1

2d = 2.2

d = 1.1 km

Given f(x)= 3|2x-4|-8
find f(-3)=

Answers

Hi there!

[tex]\large\boxed{f(-3) =22 }}[/tex]

Find f(-3) by substituting in -3 for x:

f(x) = 3|2x - 4| - 8

f(-3) = 3|2(-3) - 4| - 8

Simplify:

f(-3) = 3|-6 - 4| - 8

f(-3) = 3|-10| - 8

f(-3) = 3(10) - 8 = 22

find the value of 0.7 +15.352+2​

Answers

Answer:

wouldn't this be 18.052

Step-by-step explanation:

add 15 and 2 then add 1 (from 0.7 plus 0.3) then add the other decimals

Answer: 18.052

Step-by-step explanation:

We just need to add them all.

15.352+0.7=16.052 16.052+2=18.052

Pleas help I will give brainliest also please show how you did it please

Answers

Answer:

for n ≤ 3

we are going to put a circle on the 3 and make it filled in then you are going to start an arrow starting from the 3 going to the left all the way to the -10.

Answer:

n ≥ -1 or n ≤ 3

Combined:

-1 ≤ n ≤ 3

Since the inequalities are ≤, it'll be a closed circle

The closed circle will start AT -1 and another closed circle will end at 3

Someone Help Me Please

Answers

Answer:

y=-4x-5

Step-by-step explanation:

as considering (x,y) as(-2,3)this shows the perpendicularity

Enter the volume of the right rectangular prim in cubic inches

Answers

Answer:

602 in^2

Step-by-step explanation:

To find volume, multiply length, width, and height. In this case, it is 5, 14, and 8 3/5. I used a calculator, but if not, solve it using regular multiplication. First 5 times 14 since that is easier to get out of the way, then 8 3/5, and it is easiest to treat a fraction as a decimal when multiplying, in this case it would be 0.6. I am not going to explain how I got that since you were asking how to find volume.

which of the following phrases describes the expression 2 - 2x​

Answers

Answer:c

Step-by-step explanation:cccccc

The thickness of the backfat in pigs is used in evaluating the quality of their flesh for consumption. To compare the backfat thickness of pigs raised on two different diets, an animal researcher randomly sampled a group of pigs raised on Diet 1 and another group raised on Diet 2:
Sample Mean Sample SD Sample Size
Diet 1 3.63 cm 0.29 cm 18
Diet 2 3.37 cm 0.25 cm 18
POOLED SE 0.09
A) After confirming all relevant assumptions, you want to test if the mean backfat thicknesses of the pigs raised on these two diets differs. What is the absolute value of the test statistic?
B) If the critical value for this test is 2.032 (confirm that it is), what would be an appropriate conclusion for this test?
A. An conclusion is not warranted for this test
B. This data provides evidence that mean backfat thickness of pigs on Diet 1 is different from pigs on Diet 2 (p<.05)
C. This data provides no evidence that mean backfat thickness of pigs on Diet 1 is different from pigs on Diet 2 (p<.05)
D. This data provides evidence that diet is independent of backfat thickness (p<.05)
E. There is no evidence that diet is independent of backfat thickness (p>.05)

Answers

Answer:

A) The test statistic is approximately 7.5056

B) E. There is no evidence that diet is independent of backfat thickness

Step-by-step explanation:

The given data are;

The sample mean for pigs raised on Diet 1, [tex]\overline x_1[/tex] = 3.63 cm

The sample SD for pigs raised on Diet 1, s₁ = 0.29 cm

The number of pigs in the sample for pigs raised on Diet 1, n₁ = 18

The sample mean for pigs raised on Diet 2,  [tex]\overline x_2[/tex] = 3.37 m

The sample SD for pigs raised on Diet 2, s₂ = 0.25 cm

The number of pigs in the sample for pigs raised on Diet 2, n₂ = 18

The pooled SE = 0.09

A) The test statistic is given by the following formula;

[tex]t=\dfrac{(\bar{x}_{1}-\bar{x}_{2})}{\sqrt{\dfrac{s_{1}^{2} }{n_{1}}-\dfrac{s _{2}^{2}}{n_{2}}}}[/tex]

Therefore, we have;

[tex]t=\dfrac{(3.63-3.37)}{\sqrt{\dfrac{0.29^{2} }{18}-\dfrac{0.25^{2}}{18}}} \approx 7.5056[/tex]

The test statistic, t ≈ 7.5056

B) The degrees of freedom, df = n₁ - 1 = 18 - 1 = 17

At a confidence level of 95%, the critical value is 2.11

Given that the value of the test statistics tic if larger than the critical value, the null hypothesis is rejected and there is a difference in the backfat of the pigs on different diet

Therefore, there is no evidence that diet is independent of backfat thickness

5x + (1x+6)= 78
BARDZO POTRZEBUJĘ

Answers

Answer:   x = 12

Step-by-step explanation:  

1. add 5x + 1x which will equal 6x so now your equation is:  6x + 6 = 78

2. subtract 6 from 78 to get 72:  6x = 72

3. divide 72 by 6x to get your answer 12

Answer:

x = 12

Step-by-step explanation:

6x + 6 = 78

6x = 78 - 6

6x = 72

x = 72 / 6

x = 12

Mam nadzieję, że to pomoże!

find an ordered pair (x, y) that is a solution to the equation 4x-y=5​

Answers

Answer:

An ordered pair that is a solution to the equation is (2,3).

Step-by-step explanation:

To find an ordered pair that is a solution to the equation, we attribute a value to one of the variables(x or y), and find the other.

4x-y=5​

Using y = 3

4x - 3 = 5

4x = 8

x = 8/4 = 2

An ordered pair that is a solution to the equation is (2,3).

Whoever responds first will get marked Best!please look at the picture!Which scenario has the same area as the given figure?
A:A triangle with a base of 6 ft and a height of 10 ft.
B:A rectangle with a base of 9 ft and a height of 10 ft.
C:A parallelogram with a base of 10ft and a height of 16 ft.
D:A triangle with a base of 7 ft and a height of 24 ft.

Answers

Answer:

D) 96 is closest

Step-by-step explanation:

12x7=84

1/2(8)(4)=16

84+16=100

A = 30

B = 45

C = 160

D = 96

what is 1 plus 1 2+2 sara has this much how can she divide it to her 1 friend and her?

Answers

Answer: 7.5 each

Step-by-step explanation:

15/2

Write the directed line segment ratio as a fraction.
3:4
O [tex]\frac{3}{12}[/tex]
O [tex]\frac{4}{3}[/tex]
O [tex]\frac{3}{7}[/tex]
O [tex]\frac{4}{3}[/tex]

Answers

3:4 as a fraction is 4/3
D! The answer is 4/3

what is this figure ?

Answers

Answer:

B) rhombus

Step-by-step explanation:

the tic marks on the lines indicate that they are congruent, not parallel there is no way of knowing for sure that those lines are parallel therefore it is not a parallelogram even though it looks like it  

A 13-foot ladder leaning against a building meets the side of the building exactly 12 feet above the ground. How far from the building is the base of the ladder rounded to the nearest hundredth foot?

Answers

Answer:

At the moment in question, we have a 5-12-13 right triangle.

x^2 + y^2 = 13^2

2x dx/dt + 2y dy/dt = 0

2(5)(2/3) + 2(12) dy/dt = 0

dy/dt = -5/18 ft/s

the area is 1/2 xy, so

da/dt = 1/2 y dx/dt + 1/2 x dy/dt

= (1/2)((12)(2/3) + (5)(-5/18))

= 119/36

Step-by-step explanation:

I dont understand the first 4

Answers

Answer:

Let me see what i can do, I'll try. Hope this helps

PLEASE HELP DEW IN 1 hour

Answers

Answer: B

Step-by-step explanation:

2(—2) + 10 = 6.

2(0) + 6 = 6.

2(2) + 2 = 6.

2(4) + (—2) = 6

What 2 things put an expression in simplest form?

Answers

Answer:

Step-by-step explanation:

All you need to simplify most expressions is basic arithmetic -- addition, subtraction, multiplication, and division -- and the order of operations.

What is the value of the y-intercept of the graph of f(x) = 29(5.2)* ?

Answers

Answer:

(0,29)

Step-by-step explanation:

To find the y-intercept, substitute in

0 for x and solve for y OR use a graphing calculator.

please help with this math question! and explain to me please so i understand

Answers

Answer:

360 - 98 = 262

Step-by-step explanation:

Which of the following sets of data does NOT represent a function? Set A x y 6 3 8 4 5 7 9 2 Set B x y 0 3 1 8 2 8 3 -7 Set C x y 10 7 20 11 30 9 40 7 Set D x y 3 9 2 2 8 -3 2 1 a. Set A b. Set B c. Set C d. Set D

Answers

Answer:

Set D

Step-by-step explanation:

There's 2 different y-values for the x value, 2 in Set D

State if the triangles in each pair of similar. If so, state how you know they are similar and complete the similarity statement.


triangle UTS~ ____

a. similar, AA, UED
b. similar, SSS, UDE
c. similar, SAS, UDE
d. not similar​

Answers

Answer:

triangle UTS~∆UED by AAA axiom

if the circumference of a circle is 52 cm, what is the radius? round to the nearest tenth. PLESE HELP I DONT HAVE THAT MUCH TIME :(

Answers

Answer:

8.3

Step-by-step explanation:

Given,

Circumference of the circle = 52 cm

Therefore ,

By the problem,

[tex] = > 2\pi r = 52[/tex]

[tex] = > 2 \times 3.14 \times r = 52[/tex]

[tex] = > r = \frac{52}{3.14 \times 2} [/tex]

=> r = 8.2802547771

Rounded to nearest tenth,

=> r = 8.3 (Ans)

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