Question

Assume that we want to construct a confidence interval. Do one of the​ following, as​ appropriate: (a) find the critical value t Subscript alpha divided by 2tα/2​, ​(b) find the critical value z Subscript alpha divided by 2zα/2​, or​ (c) state that neither the normal distribution nor the t distribution applies. Here are summary statistics for randomly selected weights of newborn​ girls: nequals=239239​, x overbarxequals=33.433.4 ​hg, sequals=7.97.9 hg. The confidence level is 9595​%.

Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice.

A. t Subscript alpha divided by 2tα/2equals= nothing ​(Round to two decimal places as​ needed.)

B. z Subscript alpha divided by 2zα/2equals= nothing ​(Round to two decimal places as​ needed.)

C. Neither the normal distribution nor the t distribution applies.

Answer 1

The confidence interval for true mean based on the sample mean is

The summary statistics for randomly selected weights of newborn​ girls: ​, , .

The confidence level is 95​%.

Since the population standard deviation is not known, we use Student's t-distribution.

For

A) The critical values are .

answered by: anonymous