At your part-time job in the office, your manager requested that you examine all accounts receivable of the company, and

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At your part-time job in the office, your manager requested that
you examine all accounts receivable of the company, and then to
take a random sample of them to provide her with estimates of the
population values useful for decision making. You considered a
random sample of 48 of the accounts and obtained a mean of $138.55
and a standard deviation of $50.28. Assuming normality for the
distribution of amounts in the accounts receivable, estimate the
upper end point in a 90% confidence interval for the total amount
of the 805 accounts of the company.