Question

You have an SRS of four observations from a Normally distributed population. What critical value would you use to obtain an 80% confidence interval for the mean μ of the population?

a.1.533

b.1.638

c. 2.353

Answer 1

Solution:-

Given data:

Number of observation, n=4

Confidence interval = 80%

Here we have to find out the critical value.

Here, df = n - 1

df = 4 - 1

df = 3

Significance level, = 1 - 80%

= 1 - 0.80

= 0.20

Critical value is  .

( From t-distribution table, at df =3 and = 0.1, )

Hence, Option-b is correct answer.