Question

QUESTION 13

1. A confidence interval

		always includes the population parameter.
		decreases in width as the sample size is decreased.
		can include a value of less than 0.
		None of the above

Answer 1

A confidence interval includes the population parameter value with the probability equal to the confidence level for that confidence interval but not with 100% probability. Therefore the first statement is False here.

As the sample size is decreases, the standard error increases and hence the width of the confidence interval also increases. Therefore the width increases and hence the second statement is also False here.

A confidence interval could lie on any real number range and can include a value less than 0. Therefore only c) is true here. That is can include 0.