A random sample from a normal population yields the following 25 values:
90 87 121 96 106 107 89 107 83 92
|
117
|
93
|
98
|
120
|
97 109 78
|
87 99 79
|
|
104
|
85
|
91
|
107
|
89
|
|
(a) Calculate an unbiased estimate σˆ 2 of the population variance.
(b) Give approximate 99% con?dence interval for the population variance.
(c) Interpret your results and state any assumptions you made in order to solve the problem.