Chapter 7.1, Problem 18E

(a)

To determine

Whether the larger random sample reduces the bias of the poll result or not.

Answer to Problem 18E

The sampling variability of the sample proportion changes from state to state.

Explanation of Solution

Here, if the sample size increases then the bias will be not be affected as when the sample size increases, the sampling techniques does not get affected by the sample size.

Hence, the larger random sample reduces the bias of the poll result.

(b)

To determine

Whether the sample reduces the variability of the result or not.

Answer to Problem 18E

The sample reduces the variability of the result.

Explanation of Solution

Here, if the sample is larger; then more information can be obtained about the distribution. Thus, the variability will be reduced as the distribution allows to make more accurate estimates.

Hence, the sample reduces the variability of the result.