Sample trials = 5 Population standard deviation = 19.53. Current mean is approximately but no more than 750. Determine number of trials runs needed to make us 95% confident that the sample mean hourly yield is within a margin of error of 8 pounds of the population mean hourly yield. And number of trials needed to make us 99% confident that the sample mean hourly yield is within a margin of error of 5 pounds of the population standard deviation