Question: The mean amount of the 812 mortgages taken out in
The mean amount of the 812 mortgages taken out in a city in the past year must be estimated. Based on previous experience, a real estate broker knows that the population standard deviation is likely to be about $20,000. If a 95% confidence interval for the population mean is to extend $2,000 on each side of the sample mean, how many sample observations are needed if a simple random sample is taken?
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