statistics
posted by Sally .
a. A random sample of 25 was drawn from a normal distribution with a standard deviation of 5. The sample mean is 80. Determine the 95% confidence interval estimate of the population mean.

statistics 
MathGuru
Formula:
CI95 = mean + or  1.96(sd/√n)
sd = standard deviation
n = sample size
Substitute the values from your problem into the formula and calculate.
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