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Suppose we are interested about a confidence interval for the population mean scores on an exam....

Suppose we are interested about a confidence interval for the population mean scores on an exam. A random sample of 38 scores is taken and gives a sample mean (sample mean score) of 118. What is the 95% Error Bound (EBM) if the population standard deviation is 8 points?

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Answer #1

We need to construct the 95% confidence interval for the population mean \muμ. The following information is provided:

Sample Mean() 118
Population Standard Deviation (σ) = 8
Sample Size (N) 38

The critical value for α=0.05 is . The corresponding confidence interval is computed as shown below:

Therefore, based on the data provided, the 95\%95% confidence interval for the population mean is 115.456<μ<120.544

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