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Chapter 8: Q 78. (page 543)

The SAT againHigh school students who take the SAT Math exam a second time

generally score higher than on their first try. Past data suggest that the score increase has a standard deviation of about 50points. How large a sample of high school students would be needed to estimate the mean change in SAT score to within 2 points with 95%confidence?

Short Answer

Expert verified

Sample size is 2401.

Step by step solution

01

Given Information

It is given that (蟽)=50

Confidence Interval=95%

E=2

02

Concept Used

Formula to be used is:

n=z伪2脳蟽E2

Using table, value of Za2=1.96corresponding to 95%confidence interval.

03

Calculation

Hence, n=32脳蟽E2

=1.96脳5022

=2401

Sample size is2401

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Most popular questions from this chapter

How confident? The figure shows the result of taking 25SRSs from a Normal population and constructing a confidence interval for the population mean using each sample. Which confidence level鈥�80%,90%,95%,or99%鈥攄o you think was used? Explain your reasoning.

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estimate the confidence level, assuming that the NCAA took an SRS.

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