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To determine how well a new method of teaching vocabulary is working in a certain elementary...

To determine how well a new method of teaching vocabulary is working in a certain elementary school, education researchers plan to give a vocabulary test to a sample of 100 sixth graders. It is known that scores on this test have a standard deviation of 8. The researchers found the sample mean to be 100. Construct a 99% confidence interval for the population mean. Round your answers to whole numbers.

Math   Statistics-And-Probability   
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Answer #1

99% confidence interval for is

- Z/2 * / sqrt(n) < < + Z/2 * / sqrt(n)

100 - 2.576 * 8 / sqrt(100) < < 100 + 2.576 * 8 / sqrt(100)

98 < < 102

99% CI is ( 98 , 102 )

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