In 2001, the mean household expenditure for energy was $1493, according to data from the U. S. Energy Information Administration. An economist wants to test whether this amount has changed significantly from its 2001 level. In a random sample of 35 households, he found the mean expenditure for energy during the most recent year to be $1618, with a standard deviation $321. Conduct a hypothesis test at 10% significance level to see whether we have strong evidence to support the economist’s hypothesis.

M. cotteleer electronics supplies microcomputer circuitry to a company that incorporates microprocessors into refrigerators and other home appliances. one of the components has an annual demand of 235 units, and this is constant throughout the year. carrying cost is estimated to be $1.25 per unit per year, and the ordering (setup) cost is $21 per order. a) to minimize cost, how many units should be ordered each time an order is placed? b) how many orders per year are needed with the optimal policy? c) what is the average inventory if costs are minimized? d) suppose that the ordering cost is not $21, and cotteleer has been ordering 125 units each time an order is placed. for this order policy (of q = 125) to be optimal, determine what the ordering cost would have to be.