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 skewed

Choose the correct answer below.

A. tα/2 =2.626

B. zα/2 = 1.96

C. tα/2 =1.984

D. zα/2 = 2.575

E. Neither the normal nor the t distribution applies

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.?

98 % ; n= 19; σ = 21.4; population appears to be normally distributed

A. zα/2 = 2.33

B. tα/2 = 2.214

C. zα/2 = 2.552

D. zα/2 = 2.055

E. Neither normal nor t distribution applies

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 1.96

2. 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.