Question

The formula used to compute a confidence interval for the mean of a normal population when n is small is the following.

What is the appropriate t critical value for each of the following confidence levels and sample sizes? (Round your answers to two decimal places.)

(a) 95% confidence, n = 17
  

(b) 90% confidence, n = 12
  

(c) 98% confidence, n = 24
  

(d) 90% confidence, n = 24
  

(e) 95% confidence, n = 13


(f) 95% confidence, n = 10

Answer 1

Solution :

(a) 95% confidence, n = 17

df = 16

Critical value = 2.12
  
(b) 90% confidence, n = 12

df = 11
  
Critical value = 1.80

(c) 98% confidence, n = 24

df = 23
  
Critical value = 2.50

(d) 90% confidence, n = 24

df = 23
  
Critical value = 1.71

(e) 95% confidence, n = 13

df = 12

Critical value = 2.18

(f) 95% confidence, n = 10

df = 9

Critical value = 2.26