statistics
posted by Janelle .
A psychologist wants to estimate the variance of employee test scores. A random
sample of 18 scores had a sample standard deviation 10.4. Find a 90% confidence
2
interval for the population variance. What assumption, if any, have you made in calculating this interval estimate?

90% interval = mean ± 1.645 SD
SD^2 = variance
Assume normal distribution.
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