# Leverage

## Leverage

• Submitted By: spaniard
• Date Submitted: 11/30/2009 4:57 AM
• Words: 503
• Page: 3
• Views: 332

There are 20 points possible.

1. The January snowfall in Syracuse New York, follows a uniform distribution between 0.5 and 3.00 inches.

What is the mean rainfall for January? (1)

What is the probability of less than two inches of rain for the month. (1)

2. According to the IRS, the mean tax refund for the year 2004 was \$2,600. Assume the standard devidation is \$300 and that the amounts refunded follow a normal probability distribution. (In each case calculate the z value and the probability.)

What percent of the refunds are less than \$3000? (2)

What percent of the refunds are between \$2700 and \$2800? (2)

3. What happens to the shape of a normal distribution if the standard deviation increases while the mean stay the same?

4. The nationwide statistics exam last year had a mean of 88 and a standard deviation of 3. You assume that the results will be the same this year. What must you score to be in the top 5% (2)

5. The female students insist on having 2 members on the 4 member student council. What sampling method would you employ?
a. simple random sampling
b. systematic random sampling
c. stratified random sampling
d. cluster random sampling

6. You are in the army. It has been decided that every 15th soldier in the battalion will be sent on a dangerous mission. What kind of sampling is this?
a. simple random sampling
b. systematic random sampling
c. stratified random sampling
d. cluster random sampling

7. What is a sampling error?
a. a mistake in the calculation of a sample statistic
b. the difference between the population mean and the sample standard deviation
c. the difference between a population parameter and a sample statistic
d. a mistake in the selection of a sample

8. What is the name for the means of all possible samples, arranged into a probability distribution?
a. sampling error
b. standard normal distribution
c. sampling distribution of the sample mean
d. central limit theorem

9. With which...