Estimating mean and standard deviation from the sample ...

Find a 90% confidence interval for the difference between the two population proportions. Formula #6: Or (-0.198, -0.076) 17. Referring back to Problem 3 above, find the sample size needed so that a 90% confidence interval for the population mean weight of bricks extends an amount 0.01 on each side of the sample mean. Therefore the sample must be ................
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