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Chapter 7: Q.2 (page 459)

The Gallup Poll has decided to increase the size of its random sample of voters from about 1500people to about 4000people right before an election. The poll is designed to estimate the proportion of voters who favor a new law banning smoking in public buildings. The effect of this increase is to

(a) reduce the bias of the estimate.

(b) increase the bias of the estimate.

(c) reduce the variability of the estimate.

(d) increase the variability of the estimate.

(e) have no effect since the population size is the same

Short Answer

Expert verified

The correct answer is (c) Reduce the variability of the estimate.

Step by step solution

01

Given Information

Size the random sample of voters=1500

Size of the random sample of increased voters =4000=4000

02

Explanation

We know that the sampling procedures always cause bias and the bias is not influenced by the sample size.

Since a larger sample gives more information about the respective population; if the sample size increases then the variability is reduced.

Hence, the correct answer is (c)

That is reduce the variability of the estimate.

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