4. Compute the 90 % confidence interval of the mean salary of all math professors. A simple random sample of 36 such salaries was collected and was found to have an average of $77550. Historically,...

4. Compute the 90 % confidence interval of the mean salary of all math professors. A simple random sample of 36 such salaries was collected and was found to have an average of $77550. Historically, the population standard deviation of the salaries of all Math professors is known to be $2750. Please interpret the result
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