Question

The following data shows the number of times within a year Lucy Ricardo tried to get into one of her husbands shows. Assume that her attempts are normally distrubuted and the standard deviation is s=10.00 attempts. Construct and interpret a 95% confidence interval for the population standard deviation of the number of attempts to get into a show.

52 30 44 35 39 26

47 37 56 26 39 28

a) Indentify the degrees of freedom, n-1

b) Draw a Chi- Square distrubution with the critical values and areas labeled. State the two critical values with sub-notation.

c) Find the confidence interval for the population variance. Round to two decimal places.

d) Find the confidence interval for the population standard deviation. Round to two decimals places.

e) Interpret the results for the standard deviation confidence interval.

Answer 1

e. We are 95% confident that the population standard deviation will fall between 7.08 and 16.98 .