For Exercises 6.23 to 6.25, see page 304; for 6.26 and 6.27, see pages 305–306; for 6.28 to 6.30, see page 309; for 6.31 and 6.32, see page 311; and for 6.33, see page 313.
6.23 Company invoices.
The mean amount for all the invoices for your company last month is not known. Based on your past experience, you are willing to assume that the standard deviation of invoice amounts is about $260. If you take a random sample of 100 invoices, what is the value of the standard deviation for ?
6.23
.