Question

In order to test whether the average waiting time this year differs from last year, a sample of 25 data were collected this year with a mean of 0.74 hours and standard deviation 0.22 hours. The 99% confidence interval for banking service this year has a wider range than 95% confidence interval for banking service this year.

a.False
b.True

Answer 1

True

Explanation:

Confidence interval for banking service in a given confidence level can be calculated as M±ME where

• M is the mean banking service in the sample and
• ME is the Margin of Error

margin of error (ME) is calculated using the formula

ME=
`(t*s)/(√(N) )` where

• t is the corresponding statistic in the given confidence level

• s is the standard deviation of the sample(or of the population if it is known)

• N is the sample size

t-statistic for 99% confidence level is always bigger than 95% confidence level which makes Margin of Error bigger and thus confidence interval wider.