The cost of controlling emissions at a firm goes up rapidly as the amount of emissions reduced goes up. Here is a possible model, C(x, y) = 1,000 + 400x2 + 500y2, where x is the reduction in sulfur emissions, y is the reduction in lead emissions (in pounds of pollutant per day), and C is the daily cost to the firm (in dollars) of this reduction. Government clean-air subsidies amount to $200 per pound of sulfur and $200 per pound of lead removed. How many pounds of pollutant should the firm remove each day to minimize net cost (cost minus subsidy)?

Kiona co. set up a petty cash fund for payments of small amounts. the following transactions involving the petty cash fund occurred in may (the last month of the company's fiscal year). may 1 prepared a company check for $350 to establish the petty cash fund. 15 prepared a company check to replenish the fund for the following expenditures made since may 1. a. paid $109.20 for janitorial services. b. paid $89.15 for miscellaneous expenses. c. paid postage expenses of $60.90. d. paid $80.01 to the county gazette (the local newspaper) for an advertisement. e. counted $26.84 remaining in the petty cashbox. 16 prepared a company check for $200 to increase the fund to $550. 31 the petty cashier reports that $380.27 cash remains in the fund. a company check is drawn to replenish the fund for the following expenditures made since may 15. f. paid postage expenses of $59.10. g. reimbursed the office manager for business mileage, $47.05. h. paid $48.58 to deliver merchandise to a customer, terms fob destination. 31 the company decides that the may 16 increase in the fund was too large. it reduces the fund by $50, leaving a total of $500.

Alarge university wanted to study the relationship between completing an internship during college and students' future earning potential. prom the same graduating class, they selected a random sample of 80 students who completed an internship and 100 students who did not complete an internship and examined their salaries five years after graduation. they found that there was a statistically higher mean salary for the internship group than for the noninternship group. which of the following interpretations is the most appropriate? a. there could be a confounding variable, such as student major, that explains the difference in mean salary between the internship and no internship groups.b. we cannot infer anything from these data since the distribution of salaries is likely right skewed.c. you cannot draw any valid conclusions because the sample sizes are different.d. more students should complete internships because having an internship produces a higher salary.

You are purchasing a bond that currently sold for $985.63. it has the time-to-maturity of 10 years and a coupon rate of 6%, paid semi-annually. the bond can be called for $1,020 in 3 years. what is the yield to maturity of this bond?