Question

The makers of a soft drink want to identify the average age of its consumers. A sample of 25 consumers was taken. The average age in the sample was 31 years with a standard deviation of 3.8 years. The Margin of error of the 99% confidence interval for the average age of the consumers is

Answer 1

Explanation:

d_f=25-1=24

critical t value=tinv (0.05,24)=2.064

Margin of error=2.064×(3.8/sqrt(25))=1.86

99% confidence interval for mean

=22.5+/-1.86

=(20.64, 24.36)