Q:

To construct a confidence interval using the given confidence​ level, do whichever of the following is appropriate.​ (a) Find the critical value z Subscript alpha divided by zα/2​, ​(b) find the critical value t Subscript alpha divided by tα/2​, or​ (c) state that neither the normal nor the t distribution applies.?95 ​% ; n=100​; σ = unknown​; population appears to be skewedChoose the correct answer below.A. tα/2 =2.626B. zα/2 = 1.96C. tα/2 =1.984D. zα/2 = 2.575E. Neither the normal nor the t distribution appliesTo construct a confidence interval using the given confidence​ level, do whichever of the following is appropriate.​ (a) Find the critical value z Subscript alpha divided by zα/2​, ​(b) find the critical value t Subscript alpha divided by tα/2​, or​ (c) state that neither the normal nor the t distribution applies.?98 ​% ; n= 19; σ = 21.4​; population appears to be normally distributedA. zα/2 = 2.33B. tα/2 = 2.214C. zα/2 = 2.552D. zα/2 = 2.055E. Neither normal nor t distribution applies

Accepted Solution

A:
Answer:1:  z = 1.962:  t = 2.552Step-by-step explanation:1:  When you don't know the population standard deviation and the sample size is large, you can still use a z test because many large samples are relatively normally distributed.  A 95% confidence interval uses a z-score of 1.962.  We are told that n < 30, so we use t distribution.  Use the degrees of freedom, which is one less than the population, and the column that has 0.02 in the area of 2 tails.