A corporation plans to issue some short-term notes and is hoping that the interest it will have to pay will not exceed 11.5%. To obtain some information about this prob- lem, the corporation marketed 40 notes, one through each of 40 brokerage firms. The mean and standard deviation for the 40 interest rates were 10.3% and .31%, respec- tively. Since the corporation is interested in only an upper limit on the interest rates, find a 95% upper confidence bound for the mean interest rate that the corporation will have to pay for the notes.

Please see below for the question details. I got 34.32 for the interest, but I also got 19.68 and 32 when I reworked the problem; Please help!!!! Because of the relatively high interest rates, most consumers attempt to pay off their credit card bills promptly. However, this is not always possible. An analysis of the amount of interest paid monthly by a bank's Visa cardholders reveals that the amount is normally distributed with a mean of 27 dollars and a standard deviation of 8 dollars.Please use z-scores with at least 3 decimal places. D. What interest payment is exceeded by only 18% of the bank's Visa cardholders? Interest Payment =

An insurance company wants to make sure that its best customers (those with lowest value of insurance claims) stay with the company. To achieve this goal, the company plans to offer a 10% discount on the annual health insurance premium for customers with the lowest 20% of annual health care expenses. If the average annual health care expenses for a family of four is $3,650 with a standard deviation of $975, what is the amount of the maximum annual health care expense that will qualify for the proposed discount?

Suppose the following data show the introductory interest rates on a sample of 5 credit cards: 6, 2.7, 3.3, 5.6, 3.7. Calculate the standard deviation of the sample. Note: the numbers may be different from the last problem. (please express your answer using 2 decimal places)

Imagine that for those who meditate daily, the number of minutes in meditation has mean 35 and standard deviation 10. In a group of 200 such persons, how many are expected to meditate more than 43 minutes per day? Click the icon to view the table of z-scores. Of the 200 persons, approximately will meditate more than 43 minutes per day. (Round to the nearest whole number as needed.)

According to the New York Daily News, March 5, 2014, people 65 years and older watch an average of 50.5 hours of TV per week. We will estimate the standard deviation to be 12.7 hours per week. Your town has many social programs for senior citizens which may reduce the amount of TV that older people watch. You want to find out if it is true that people 65 and older in your town watch less than 50.5 hours of TV per week. So, you sample 40 people 65 and older in your town. You find that the average time that the 40 people watch per week is 45.8 hours. Can the claim be supported to a level of significance of α = .02, test the hypothesis?

Suppose the returns of a particular group of mutual funds are normally distributed with a mean of 9.9% and a standard deviation of 3.7%. If the manager of a particular fund wants his fund to be in the top 10% of funds with the highest return, what return must his fund have?