Question

Suppose the consumer group used a sample size of 50 instead of 100 for each airline. When all other things remain the same, what effect would the decrease in sample size have on the interval?

Answer 1

Width of confidence interval will increase.

Explanation:

The sample size as an effect on the width of the confidence interval being calculated as it determines the value of the error margin. In general, increasing the sample size reduces the width of the confidence that interval while decrease in its value increases the error margin and hence the confidence interval.

Confidence interval :

Xbar ± Error margin

Error margin = Tcrit * s/ sqrt(n)

n = sample size

Being the denominator, a decrease in its value will result in an increase in error margin.