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Suppose that you have a sample size n = 100 with mean x = 5 and standard deviation s = 2, and that you are to construct a confidence interval for the population mean \mu μ . If, after you obtain the confidence interval, you find it to be too wide, which of the following remedial steps can you take to reduce the width of the confidence interval?

A. To construct a 90% confidence interval instead of a 95% one.
B. To construct a 99% confidence interval instead of a 95% one.
C. To re-do the 95% confidence interval with only a half pf the sample data.

Respuesta :

Answer:

Option A

Step-by-step explanation:

Given that for a sample size n =100, with mean x = 5 and standard deviation s = 2, a confidence interval was constructed

This was very wide and steps have to be taken to reduce its width

Confidence interval = Mean ±Margin of error

Margin of error = Critical value * std error = Critical value * std dev/sqrt n

Thus confidence interval can be narrowed by

i) either reducing confidence level from 95% to 90%

or ii) by increasing sample size

or iii) by reducing std deviation.

Hence here correct answer is

A. To construct a 90% confidence interval instead of a 95% one.

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