A magazine includes a report on the energy costs per year for​32-inch liquid crystal display​ (LCD) televisions. The article states that 14 randomly selected​ 32-inch LCD televisions have a sample standard deviation of ​$3.42 . Assume the sample is taken from a normally distributed population. Construct 98 ​% confidence intervals for​ (a) the population variance sigma squared and​ (b) the population standard deviation sigma .
Interpret the results. ​(a) The confidence interval for the population variance is ​(___,___ ​). ​(Round to two decimal places as​ needed.)
Interpret the results. Select the correct choice below and fill in the answer​ box(es) to complete your choice. ​(Round to two decimal places as​ needed.)
A. With 98 ​% ​confidence, you can say that the population variance is less than ___.
B. With 2 ​% ​confidence, you can say that the population variance is between nothing and ___ .
C. With 98 ​% ​confidence, you can say that the population variance is between ___ and ___ .
D. With 2 ​% ​confidence, you can say that the population variance is greater than ___
​(b) The confidence interval for the population standard deviation is ​(n___,___​). ​(Round to two decimal places as​needed.)
Interpret the results. Select the correct choice below and fill in the answer​ box(es) to complete your choice. ​(Round to two decimal places as​ needed.)
A. With 98​% ​confidence, you can say that the population standard deviation is between ___ and ___ dollars per year.
B. With 98​% ​confidence, you can say that the population standard deviation is greater than ___ dollars per year.
C. With 2​% ​confidence, you can say that the population standard deviation is less than ___ dollars per year.
D. With 2​% ​confidence, you can say that the population standard deviation is between ___ and ___ dollars per year.

Answer:

a

The confidence interval for the population variance is ​[tex] 5.49 < \sigma^2 < 37.02 [/tex]  

The correct option is  C

b

The confidence interval for the population standard deviation is [tex] 2.34 < \sigma < 6.08 [/tex]

The correct option is  A

Step-by-step explanation:

From the question we are told that

    The sample size is  n =  14

    The standard deviation is  [tex]s = \$3.42[/tex]

Generally the degree of freedom is mathematically represented as

     [tex]df =  14 -1[/tex]

=>   [tex]df =  13 [/tex]    

Given that the confidence level is  98%  then that level of significance is  

     [tex]\alpha = (100 -98) \%[/tex]

=>  [tex]\alpha = 0.02[/tex]

Generally the 98% confidence interval for the variance  is mathematically represented as

     [tex]\frac{(n- 1) s^2}{x^2 _{[\frac{\alpha }{2} , df]}}  < \sigma^2 < \frac{(n- 1) s^2}{x^2 _{[1- \frac{\alpha }{2} , df]}}[/tex]

=> [tex]\frac{(14- 1) (3.42)^2}{x^2 _{[\frac{0.02 }{2} , 13]}}  < \sigma^2 < \frac{(14- 1) (3.42)^2}{x^2 _{[1- \frac{0.02 }{2} , 13]}}[/tex]

From the chi -distribution table  

     [tex]x^2 _{[1- \frac{0.02 }{2} , 13]} = 4.107[/tex]

and

    [tex]x^2 _{[\frac{0.02 }{2} , 13]} = 27.689[/tex]

So

=> [tex]\frac{(14- 1) (3.42)^2}{27.689}  < \sigma^2 < \frac{(14- 1) (3.42)^2}{4.107}[/tex]    

=> [tex] 5.49 < \sigma^2 < 37.02 [/tex]    

Generally the 98% confidence interval for the standard deviation   is mathematically represented as

   [tex]\sqrt{\frac{(n- 1) s^2}{x^2 _{[\frac{\alpha }{2} , df]}}}   < \sigma <\sqrt{ \frac{(n- 1) s^2}{x^2 _{[1- \frac{\alpha }{2} , df]}}}[/tex]

=> [tex]\sqrt{5.49}  < \sigma < \sqrt{37.02 }[/tex]

=> [tex] 2.34 < \sigma < 6.08 [/tex]

i cant find the answer to 2 1/4 times 1/6?.. can someone help a kid out

Juan’s cell phone company charges $35 a month for phone service with limited data for every gigabyte of data overage the company charges $15 write an equation that represents how many gigabytes one goes over in a month if his bill was $110

Y-4>3 solve the question

A pharmaceutical sales representative gets paid $50,000 annually plus
3.5% commission on total sales. This year he sold $420,000 in
pharmaceuticals. What are his annual total earnings?

What’s the value of y in this picture

help please !!!!!!!!!!!!!

A popular restaurant advertises that it delivers its orders within 30 minutes. Suppose the average delivery time for one store is 27 minutes with a standard deviation of three minutes. One particular order delivery has a z-score of –2.15. Which of the following statements is not a correct interpretation?

A.The delivery time was 2.15 standard deviations below the average delivery time.
B.The delivery time was less than the average delivery time by 2.15 standard deviations.
C.The delivery time was faster than the average delivery time by 2.15 standard deviations.
D.The delivery time was slower than the average delivery time by 2.15 standard deviations.

Ik y’all good at math, help me out yall!

What decimal is equivalent to StartFraction 8 over 100 EndFraction

someone help please!!

Find the equation of the line passing through the points (-2,-4) and (7,23)

This table gives a few (x, y) pairs of a line in the coordinate plane. What is the x-intercept of the line?

A mug is 3/7 full. The mug contains 1/2 cup of water. Find the capacity of the mug

How is 5 represented in 6.75

what is the place value of the 6 in 976.14
​

Which shows another way to write 9.54?
O 0.5 + 0.04
O 9+ 0.4 + 0.05
O (9 * 1) + (5 x 0.1) + (4 x 0.01)
O (9 x 0.1) + (5 x 0.01) + (4 x 0.001)

someone help me on 2 and 3 plssssss

To solve the problem -9 + 18 what is the first step?
a. KCO (keep change fli[p)
b. Subtract 18 - 9
c. Subtract 9 - 18
d. Add 9 + 18

How do you solve this? Without going into anything to complicated as this should be Year 10 maths

Eight more than.twice an number is four less than the same number

The following are a list of variables that will almost certainly vary across students in a large undergraduate introductory statistics course.
(a) Favorite beverage
(b) Year of birth
(c) Typing speed
(d) Handedness (e.g., left or right handed)
(e) Age
(f) Occupation
(g) Self-report of Assertiveness
For questions 1a to 1d that follow choose the variable or variables that best represent the level of measurement.
a) Which variables would typically be measured on a nominal scale of measurement?
b) Which variable would likely be measured on an interval, but not a ratio scale?c) Which two variables are most likely to be measured on a ratio scale?d) As typically measured, which variable represents at least an ordinal scale of measurement, but probably not a true interval scale?

PLEASE HELP PLEASE!!
Complete the following statement to estimate the root of 75 to the nearest tenth. Use numbers that are closest to the root of 75

If necessary, combine like terms. (5x+1)(5x-1)

CHECK PHOTO Intercepts of the graph BE SURE TO BE CORRECT PLEASE no work needed

Help me please!!..,,

600 students are studying in a private
school, the average monthly fee of a
student is Rs. 1200. How much amount for
tax does the school pay to the government
as education service tax at the rate of 1% in
a year? *​

5|7+4x|-7=48
Please help

ASAP!!! PLEASE HELP
10 points

Which statement describes the inverse of m(x) = x^2 – 17x?


a. The domain restriction x ≥ StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction minus StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


b. The domain restriction x ≥ StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction + StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


c. The domain restriction x ≥ Negative StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction minus StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


d.The domain restriction x ≥ Negative StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction + StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .

Marking Braniest!!! What is 100÷4÷4÷4