Question

A simple random sample of size n is drawn from a population that is normally distributed. The sample​mean,

x overbar

​,

is found to be

105

​,

and the sample standard​deviation,s, is found to be

10

.

​(a)Construct

an

80

​%

confidence interval about

mu

if the sample​size,n, is

26

.

​(b)Construct

an

80

​%

confidence interval about

mu

if the sample​size,n, is

16

.

​(c)Construct

a

70

​%

confidence interval about

mu

if the sample​size,n, is

26

.

​(d)Could we have computed the confidence intervals in parts​(a)-(c)if the population had not been normally​distributed?

Answer 1