Question

In: Statistics and Probability

1. a) Suppose average monthly sales for retail locations across the United States are approximately normally...

1. a) Suppose average monthly sales for retail locations across the United States are approximately normally distributed with variance σ^2= 5200. We took a sample of size 50 and found ̄x= 12018,  Using this, conduct a hypothesis test with α= 0.05 to test the null hypothesis that the mean is 12000 vs. the alternative hypothesis that it is not. For full credit, state the null and alternative hypothesis, the test statistic, the rejection region, and your conclusion.

b)Using the setup from part a, if we know that the true mean is 12030, what is the probability of a type II error?

c)Using the setup from part a, what would be the p-value of this test? Would you reject the null hypothesis if α= 0.01? How about if α= 0.1

d)Using the set up from part a, perform the hypothesis test again, but now use the alternative hypothesis that the mean is actually greater than 12000.

e)Using the setup from part a, if we know the true mean is 12030 and we want the probability of a type I error to be 0.05 and the probability of a type II error

to be 0.10, what is the minimum sample size required to ensure this?

Solutions

Expert Solution


Related Solutions

1. a) Suppose average monthly sales for retail locations across the United States are approximately normally...
1. a) Suppose average monthly sales for retail locations across the United States are approximately normally distributed with variance σ^2= 5200. We took a sample of size 50 and found ̄x= 12018,  Using this, conduct a hypothesis test with α= 0.05 to test the null hypothesis that the mean is 12000 vs. the alternative hypothesis that it is not. For full credit, state the null and alternative hypothesis, the test statistic, the rejection region, and your conclusion. b)Using the setup from...
The Cold Mountain Furnace Company is a retail store with locations across the eastern United States....
The Cold Mountain Furnace Company is a retail store with locations across the eastern United States. The company’s projected income statement for its first year of operations, which ends December 31, 2018, and its projected balance sheet as of December 31, 2018, are shown below: Sales $ 4,000,000 Cost of Goods Sold 2,300,000 Gross Margin 1,700,000 Selling and Administrative Expenses 800,000 Net Income $    900,000 Cash $   660,000 Accounts receivable 150,000 Inventory 400,000 Property, plant, and equip. (net of accum....
Japanese automobiles comprise approximately 20% of all new car sales in the United States. Suppose a...
Japanese automobiles comprise approximately 20% of all new car sales in the United States. Suppose a state licensing office received 100 requests for license plates for new cars during a given week.       a) What is the probability that 25 or more of the license requests are for Japanese cars?       b) What is the probability that no more than 10 of the requests are for Japanese cars?       c) What is the probability that at least 10, but no...
According to actuarial tables, life spans in the United States are approximately normally distributed with a...
According to actuarial tables, life spans in the United States are approximately normally distributed with a mean of about 75 years and a standard deviation of about 16 years. 1) Find the probability that a randomly selected person lives between 60 less than 90 years. 2) Find the probability that a randomly selected person lives less than 50 years or more than 100 years. 3) Find the probability that a randomly selected person lives exactly 75 years. 4) What age...
Suppose that the final grades in a stats course are approximately Normally distributed, with an average...
Suppose that the final grades in a stats course are approximately Normally distributed, with an average grade of 83 and a SD of 5. A student is randomly selected. a.) what is the probability that the selected student received an A (at least 90)? b.) the students know that their final grade is at the 81st percentile. Show whether or not that students grade is an A. c.) if the students final grade is a least a B-, what is...
A survey of CPAs across the United States found the average net income for sole proprietor...
A survey of CPAs across the United States found the average net income for sole proprietor CPAs is $114,300. Because this survey is now more than 5 years old, an accounting researcher wants to test this figure by taking a random sample of 36 sole proprietor accountants in the United States to determine whether the average net income has increased. Only 500 sole proprietorships practice in the US. The sample of 36 sole proprietor accountants had a mean of $119,000...
A survey of CPAs across the United States found the average net income for sole proprietor...
A survey of CPAs across the United States found the average net income for sole proprietor CPAs is $114,300. Because this survey is now more than 5 years old, an accounting researcher wants to test this figure by taking a random sample of 36 sole proprietor accountants in the United States to determine whether the average net income has increased. Only 500 sole proprietorships practice in the US. The sample of 36 sole proprietor accountants had a mean of $119,000...
The average monthly mortgage payment including principal and interest is $982 in the United States. If...
The average monthly mortgage payment including principal and interest is $982 in the United States. If the standard deviation is approximately $180 and the mortgage payments are approximately normally distributed, find the probability that a randomly selected monthly payment is: A. Between $800 and $1150 B. Less than $1,000
The money supply for the United States is approximately $15 trillion, and average real GDP growth...
The money supply for the United States is approximately $15 trillion, and average real GDP growth is three percent. If velocity decreases from zero to negative two percent, what value of U.S. Treasury Securities should the Fed buy or sell to target two percent inflation if the reserve ratio is ten percent. Report an open market purchase as a positive number, a sale as a negative number, and round to the nearest billion dollars.
1.A stockpile of approximately 50 metric tons of plutonium exists in the United States as a...
1.A stockpile of approximately 50 metric tons of plutonium exists in the United States as a result of disassembling warheads from the nuclear arms race. What is the likely fate of this plutonium? (Hint: Search for plutonium disposal. Try also including United States and DOE in your search string.) a. Some propose that the plutonium be sent to local nuclear power plants to “burn” as fissionable fuel. What are the advantages and disadvantages of such a course of action? b....
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT