Which of the following is correct?
a) there is no firm mathematical relationship between marginal utility and total utility.
b) total utility is equal to the change in marginal utility from consuming an additional unit of a product.
c) if marginal utility is diminishing and is a positive amount, total utility will increase.
d) if marginal utility is diminishing, total utility must also be diminishing.

Problem 2-18 job-order costing for a service company [lo2-1, lo2-2, lo2-3]speedy auto repairs uses a job-order costing system. the company's direct materials consist of replacement parts installed in customer vehicles, and its direct labor consists of the mechanics' hourly wages. speedy's overhead costs include various items, such as the shop manager's salary, depreciation of equipment, utilities, insurance, and magazine subscriptions and refreshments for the waiting room. the company applies all of its overhead costs to jobs based on direct labor-hours. at the beginning of the year, it made the following estimates: direct labor-hours required to support estimated output 10,000fixed overhead cost $ 90,000variable overhead cost per direct labor-hour $ 1.00 required: 1. compute the predetermined overhead rate.2. during the year, mr. wilkes brought in his vehicle to replace his brakes, spark plugs, and tires. the following information was available with respect to his job: direct materials $ 600direct labor cost $ 180direct labor-hours used 2 compute mr. wilkes' total job cost. 3. if speedy establishes its selling prices using a markup percentage of 30% of its total job cost, then how much would it have charged mr. wilkes?

Acompany is developing a new high­performance wax for cross country ski racing. in order to justify the price marketingwants, the wax needs to be very fast. specifically, the mean time to finish their standard test course should be less thanseconds for a former olympic champion. to test it, the champion will ski the course 8 times. the champion's times(selected at random) are 59.9 61.9 48.8 52.2 46.6 45.3 50.6 and 41.1 seconds to complete the test course. complete parts a and b below.a) should they market the wax? assume the assumptions and conditions for appropriate hypothesis testing are metfor the sample.assume=0.05. what are the null and alternative hypotheses? choose the correct answer below.b) suppose they decide not to market the wax after the test, but it turns out that the wax really does lower the champion'saverage time to less thanseconds. what kind of error have they made? explain the impact to the company of such anerror.

In order to gauge public opinion about how to handle iran's growing nuclear program, a research group surveyed 1010 americans by telephone and asked them to rate the threat iran's nuclear program poses to the world on a scale of 1 to 10. describe the population, sample, population parameters, and sample statistics. identify the population in the given problem. choose the correct answer below.