HANDWRITTEN RESPONSE WILL BE BETTER!

1. A vending machine company wants to adjust its machines to accept dollar coins. How many such coins must be sampled in order to be 99% confident that the sample mean is within 0.03 g of the population mean for all dollar coins. Assume the population standard deviation is 0.08 g.

2. A.) A tire company manufactures tires with a mean life of 43,000 miles and a standard deviation of 3900 miles. The company wants to issue a guarantee for the tires, but does not want to replace more than 4 % of the tires sold. How many miles should the tires be guaranteed for? (Hint, watch out for the sign of Z.)

B.) If the company expects to sell 90,000 tires in a year, how many tires can the company expect to replace under the guarantee.