Question 1
Explain four ways that researchers can collect samples for research studies.
Write a multi-paragraph response.
Question 2
What is a sampling error? How can these types of errors be reduced?
Question 3
The Department of Labor would like to estimate the average weekly wages for US adults with a margin of error equal to $20. Determine the sample size needed to construct a confidence interval for this estimate using a confidence level of 90%. Assume the population standard deviation for the weekly wage is $160.
Question 4
In July 2010, a survey conducted by Webroot, a software security firm, found that 32% of the respondents use the same password for all of the social networking web sites they log on to (which, by the way, is not the best idea). Suppose a follow-up survey was conducted in late 2010 to investigate if the proportion had changed. Out of a random sample of 225 Internet users, it was found that 86 used the same password for all their social networking web sites. State the null and alternative hypothesis.
Question 5
What is the difference between a probability and a non-probability sample?
Question 6
Describe hypothesis testing for population proportions with regards to the p-value.
Question 7
Define margin of error.
Question 8
How does a Type I error differ from a Type II error?
Question 9
It is commonly known that approximately 10% of the population is left-handed. Nike Golf would like to estimate the proportion of left-handed golfers in order to plan the schedule of golf club production. Assume Nike collected a sample of 200 golfers. What is the probability that more than 12% of the golfers in the sample are left-handed?
Question 10
What is the p-value equivalent to with regards to hypothesis testing?
Select one:
a. Alternate hypothesis
b. Null hypothesis
c. Critical value
d. Observed level of significance
Question 11
What does a 10% significance level mean?
READING MATERIALS:
http://onlinestatbook.com/2/tests_of_means/testing_means.html
You may download the eBook from this link: Principles of Business Statistics