# statistics

The income of college students is normally distributed with a mean income per year is \$12,000 and a standard deviation of \$6,000.
a)If we randomly sample 25 college students, what is the probability that the average income of our sample is less than \$4,000?
b)If we randomly sample 9 college students, what is the probability that the average income is between \$5000 and \$20,000?

1. 👍 0
2. 👎 0
3. 👁 167
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 proportions related to the Z scores.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### finance (firm's net income)

If a firm has a break-even point of 20,000 units and the contribution margin on the sirm's single product is \$3.00 per unit and fixed costs are \$60,000, what will the firm's net income be at sales of 30,000 units? o.k. the break

2. ### Calculus

New York state income tax is based on taxable income which is part of a person's total income. The tax owed to the state is calculated using taxable income (not total income). In 2005, for a single person with a taxable income

3. ### Finance 200

11. The Sterling Tire Company’s income statement for 2008 is as follows: Given this income statement, compute the following: STERLING TIRE COMPANY Income Statement For the Year Ended December 31, 2008 Sales (20,000 tires at \$60

4. ### accounting

Total Assets Total Liabilities Beginning of the year \$550,000 \$215,000 End of the year 844,000 320,000 On the basis of the preceding data and the following additional information for the year, determine the net income (or loss) of

1. ### Math

A retired couple needs \$12,000 per year in income to supplement their Social Security. They have \$150,000 to invest to obtain this income. They have decided on two investment options: AA bonds yielding 10% per annum and a bank CD

2. ### Income Tax - Accounting. Help Me Please.

Tax Rates, latesha, a single taxpayer, had the following income and deductions for the year 2009. INCOME Salary \$60,000 Business Income \$25,000 Intrest income(bonds)\$10,000 Tax-exempt bond interes \$ 5,000 ________ TOTAL INCOME

If 99 people had a mean income of \$12,000, how much is the mean income increased by the addition of a single income of \$200,000?

4. ### ACC 233-INCOME TAX

Tax Rates, latesha, a single taxpayer, had the following income and deductions for the year 2009. INCOME Salary \$60,000 Business Income \$25,000 Intrest income(bonds)\$10,000 Tax-exempt bond interes \$ 5,000 ________ TOTAL INCOME

1. ### fin

1. A financial institution has the following market value balance sheet structure: (LG 19-1) Assets Liabilities and Equity . Cash \$ 1,000 Certificate of deposit \$ 10,000 Bond 10,000 Equity 1,000 Total assets \$11,000 Total
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}