Question

The following values are drawn from a normal population. (You may find it useful to reference the appropriate table: chi-square table or F table)

19 34   27 22 22 28 23 18 Cli

a. Calculate the point estimates for the population variance and the population standard deviation. (Round your answers to 4 decimal places.)

Population variance _____

Population standard deviation _____

b. Construct the 95% confidence interval for the population variance and the population standard deviation. (Round intermediate calculations to at least 4 decimal places and final answer to 2 decimal places.)

Population variance _____

Population standard deviation _____

Answer 1

a) Point estimate of population variance is the sample variance

where

Point estimate of population standard deviation is sample standard deviation

= 5.2763

b) 95% confidence interval for population variance is

degrees of freedom = 8-1=7

Thus for 95% confidence ,

( from chi square table with df = 7)

95% confidence interval for population variance

= (12.17 , 115.32  )

95% confidence interval for population standard deviation is

=

= (3.49 , 10.74)