# Statistics

Suppose the mean income of 35-year-olds in the U.S. is \$25,000. A random sample of 150 35-year-olds in California results in a sample mean income of \$26,600 and a sample standard deviation of \$3800. At the 5% significance level, can we conclude that the true mean income of 35-year-old Californians is greater than that of the nation, in general?

1. 👍
2. 👎
3. 👁
1. Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√(n-1)

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

1. 👍
2. 👎

## Similar Questions

1. ### statistic****help*****

Show all your work. Indicate clearly the methods you use because you will be graded on the correctness of your methods as well as on the accuracy of your results and explanation. A simple random sample of adults living in a suburb

2. ### STATISTIC***HELP

Show all your work. Indicate clearly the methods you use because you will be graded on the correctness of your methods as well as on the accuracy of your results and explanation. A simple random sample of adults living in a suburb

3. ### Economics

Mallory's total income last year was \$24,000, but she could deduct \$12,000 for various reasons. Her taxable income equals the amount left over after deductions. If she had to pay 15 percent of her taxable income in federal income

4. ### Statistics

In a study by Peter D. Hart Research Associates for the Nasdaq Stock Market, it was determined that 20% of all stock investors are retired people. In addition, 40% of all adults invest in mutual funds. Suppose a random sample of

1. ### econ

Frank's nominal income in 1998 is \$45,000. Suppose the CPI in 1998 is 150. What is Frank's real income? a. \$51,750 b. \$45,000 c. \$38,250 d. \$30,000 can you show me the calculations real income in what year's dollars. Real income

2. ### Math

An insurance company wishes to examine the relationship between income (in \$,000) and the amount of life insurance (in \$,000) held by families. The company drew a simple random sample of families and obtained the following

3. ### sample size question

A federal funding program is available to low-income neighborhoods. To qualify for funding, a neighborhood must have a mean household income of less than \$15,000 per year. Neighborhoods with mean annual household income of \$15,000

4. ### accounting

The condensed income statement for a business for the past year is as follows: ​ Product: white, black Sales white: \$ 750,000 black: \$550,000 Less variable costs white: 400,000 black: 380,000 Contribution margin white: \$350,000

1. ### math URGENT!

28. You are surveying students to find out their opinion of the quality of food served in the school cafeteria. You decide to poll only those students who buy hot lunch on a particular day. Is your sample random? Explain. 29. Ira

2. ### accounting

Did I do any of this right and how do I figure Retain earnings (where does net income and dividends come from? Cash .05(\$1,150,000) = \$57,500 Accounts Receivable .15(\$1,150,000) = \$172,500 Inventory .25(\$1,150,000) = \$287,500

3. ### Statistics

A student group claims that first-year students at a university must study 2.5 hours (150 minutes) per night during the school week. A skeptic suspects that they study less than that on the average. A class survey finds that the

4. ### math

I was given a table that showed a simple random sample of adults' age and annual income living in suburb of a large city. a) What is the probability that a person chosen at random from those in this sample will be the 31-45 age