A government worker surveys a number of households and comes up with the following information: there were a total of 90 people in the households, 10 of the people were children under 16, 10 of the people were retired but still capable of working, 35 people had full-time jobs, 5 had part-time jobs, 5 were stay-at-home parents, 5 were full-time students over the age of 16, 5 were disabled people who could not work, 10 people had no job but were looking for jobs, and there were 5 people who wanted a job but were not looking for a job. According to the information in the survey, the unemployment rate is:

You are the manager of a large crude-oil refinery. as part of the refining process, a certain heat exchanger (operated at high temperatures and with abrasive material flowing through it) must be replaced every year. the replacement and downtime cost in the first year is $165 comma 000. this cost is expected to increase due to inflation at a rate of 7% per year for six years (i.e. until the eoy 7), at which time this particular heat exchanger will no longer be needed. if the company's cost of capital is 15% per year, how much could you afford to spend for a higher quality heat exchanger so that these annual replacement and downtime costs could be eliminated?