1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alexxandr [17]
3 years ago
8

A group of physical education majors was discussing the heights of female runners and whether female runners tended to be tall,

on the average. They decided to estimate the mean height of female runners. A sample of 12 runners showed a sample mean height of 65.80 inches and a sample standard deviation of 1.95 inches. Assume the population is approximately normal. Find a 90% confidence interval for the mean µ of the population of female runners from which the 12 runners were selected.

Mathematics
1 answer:
Anna11 [10]3 years ago
8 0

Answer:

The 90% confidence interval for the mean µ of the population of female runners.

( 65.0328 , 66.5672)

Step-by-step explanation:

<u>Step(i)</u>

Given  A sample of 12 runners showed a sample mean height of 65.80 inches and a sample standard deviation of 1.95 inches.

Given sample size is n = 12 <30 so small sample

Given sample mean (x⁻) = 65.80 inches

sample standard deviation (S) = 1.95 inches.

<u>Step(ii)</u>

Assume the population is approximately normal.

The 90% confidence interval for the mean µ of the population of female runners.

(x^{-} - t_{\alpha } \frac{S}{\sqrt{n} } ,x^{-} +t_{\alpha } \frac{S}{\sqrt{n} } )

substitute  all above interval

(65.80 - t_{\alpha } \frac{1.95}{\sqrt{12} } ,65.80 +t_{\alpha } \frac{1.95}{\sqrt{12} } )

The degrees of freedom γ=n-1 = 12-1=11

From t- table = 1.363 at 90 % 0r 0.10 level of significance

(65.80 -1.363 \frac{1.95}{\sqrt{12} } ,65.80 +1.363 \frac{1.95}{\sqrt{12} } )

on calculation , we get

(65.80 -0.7672 ,65.80 + 0.7672)

( 65.0328 , 66.5672)

You might be interested in
What is 23.791 rounded to the nearest tenth?
sergejj [24]
The nearest tenth would be the first decimal place, so the answer would be 23.8
6 0
3 years ago
Factor x^2-2x-4 PLEASE ANSWER QUICKLY!!! I WILL GIVE POINTS!!! DBA IS TODAY!!!!
Thepotemich [5.8K]

To factor x²-2x-4, you are looking to answer three questions.

1) What pair of numbers multiplies to 4?

2) What pair of numbers multiplies to 1?

3) Do these pairs when multiplied together, add/subtract to the middle term?

To answer (1), our pairs are 2 and 2, 4 and 1. Since there's a negative with 4 at the end (from question one), the signs will be opposite.

To answer (2), only pair multiplies to 1 - 1 and 1. Let's try both pairs from 1.

(x-4)(x+1) The middle term here is -3x. Nope.

(x-1)(x+4). The middle term here is 3x. Nope.

(x-2)(x+2) The middle term is 0x (or no middle term). Nope.

So x²-2x-4 does not factor.

4 0
3 years ago
What is the area of the triangle shown below?<br> 5<br> 5<br> 8<br> units2
natima [27]

Answer:

your answer is 12 units

Step-by-step explanation:

I hope it helps

3 0
3 years ago
The results of a car race are shown. How much faster did Evans drive per lap than loza?
Lelechka [254]
Evans finishes 42 laps in 96,6 mins and Loza finished 38 laps in 102,6 mins

Evans. 96,6÷42= 2,30 mins
Loza . 102,6÷38= 2,70 mins

2,70 mins - 2,30 mins
= 40 secs and Evan is faster with 40secs in each lap.
8 0
4 years ago
Solve for x and y 9/x-4/y=8
borishaifa [10]
You can solve <span>9/x-4/y=8 for x or for y but NOT at the same time.

Solving for x:  </span><span>9/x-4/y=8       Mult all 3 terms by xy to eliminate the fractions.

9(xy)/x - 4xy/y = 8xy         =>       9y - 4x = 8xy, or 9y = 4x + 8xy = 4x(1+2y)

                                                                        then 9y = x [ 4(1+2y) ]
                                                                                     9y
                                                            therefore x = ------------
                                                                                  4(1+2y)

Solve for y using a similar approach.

</span>
7 0
3 years ago
Other questions:
  • A local band is holding a concert. The price of a ticket to the concert is $15. The band must sell enough tickets to cover at le
    7·1 answer
  • Which of the following points are NOT coplanar in this image <br> -please help-
    11·1 answer
  • -1 + r &gt;_4 solve it
    10·1 answer
  • The total cost of running a business is based on its expenses
    11·1 answer
  • The midpoint of a line segment with end points as (-10, y1) and (-6, 7) is (-8, 6). What is the value of y1?
    14·1 answer
  • The average fine for entering a national Forest wilderness without a permit increased from $65 to $78. What rate of increase is
    13·2 answers
  • In a school, 40% of the students have brown eyes. Find the experimental probability that in a group of 4 students, at least one
    11·1 answer
  • A poll of a registered voters is a small town is taken to determine their preferences in the national Presidential election. The
    5·2 answers
  • All the cubes root of <br><img src="https://tex.z-dn.net/?f=%20%5Csqrt%7B3%20%2B%20i%7D%20" id="TexFormula1" title=" \sqrt{3 + i
    6·1 answer
  • Given 3x+y=1
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!