A Random Sample of 121 Checking Accounts at a Bank

question 28

Essay

A random sample of 121 checking accounts at a bank showed an average daily balance of $280. The standard deviation of the population is known to be $66.
a.Is it necessary to know anything about the shape of the distribution of the account balances in order to make an interval estimate of the mean of all the account balances? Explain.
b.Find the standard error of the mean.
c.Give a point estimate of the population mean.
d.Construct a 80% confidence interval estimates for the mean.
e.Construct a 95% confidence interval for the mean.

---

Definitions:

Work in Process Inventory

This inventory category includes items that are in the production process but are not yet completed.

Cost of Goods Manufactured

The total production cost of goods completed during a specific period, including materials, labor, and overhead.

Total Manufacturing Costs

The cumulative cost of materials, labor, and overhead expended on the production of goods.

Gross Profit

The difference between sales revenue and the cost of goods sold, representing the profit from buying and selling goods before administrative and other expenses.