After computing a confidence interval, the investigator believes that the results are meaningless because the width of the interval is too large. In reconstructing the interval, the investigator should
A) decrease the sample size
B) increase the level of confidence
C) increase the sample size
D) reduce the population variance
E) decrease the sample size and increase the level of confidence

Question

Quizplus · Accepted Answer

Increasing the sample size will reduce the standard error and thus decrease the width of the confidence interval. This will make the results more meaningful. Reducing the population variance will also decrease the width of the interval, but this may not be achievable in practice. Decreasing the sample size or increasing the level of confidence will increase the width of the interval, worsening the situation. Therefore, the best choice is to increase the sample size.

After Computing a Confidence Interval, the Investigator Believes That the Results