business statistics 89
Question 1
Professor Nord stated that the mean score on the final exam from all the years he has been teaching is a 79%. Colby was in his most recent class, and his classâ€™s mean score on the final exam was 82%. Colby decided to run a hypothesis test to determine if the mean score of his class was significantly greater than the mean score of the population. Î± = .01.
What is the mean score of the population?
What is the mean score of the sample?
Is this test one-tailed or two-tailed? Why?
What is the null hypothesis in this case?
If p = 0.29, should Colby reject or fail to reject the null hypothesis?
What should Colbyâ€™s statement of conclusion be? (This circles back to what is being tested).
The next two ask you do to a hypothesis test. Remember, hypothesis tests follow a series of steps. They are not just a computer printout. Make sure if you use a computer printout, you identify which parts of the printout apply to the problem. All of the parts of the printout will NOT apply.
Question 2
A sample of 22 account balances of a credit company showed a mean customer balance of $4,300, but the marketing manager claimed that the mean balance for the population was $4450. The marketing manager did NOT have the population standard deviation, but the sample standard deviation was found to be $400. Use the p-value approach to conduct a full hypothesis test(all steps) that can be used to determine whether the mean of all account balances is significantly different from $4440. Let Î± = .05.
Question 3
A sample of 150 homes for sale in ABC City showed a mean asking price of $233,000, but the city claimed that the mean asking price for the population was $255,000. The population standard deviation of all homes for sale was $11,000. Use the p-value approach to conduct a full hypothesis test (all steps) that can be used to determine whether the mean asking price is significantly less than $255,000. Let Î± = .10.
Question 4
During the recent primary elections, the democratic presidential candidate showed the following pre-election voter support in Alabama and Mississippi.
State |
Voters Surveyed |
Voters in favor of Democratic Candidate |
Alabama |
710 |
352 |
Mississippi |
915 |
480 |
We want to determine whether or not the PROPORTIONS of voters favoring the Democratic candidate were the same in both states. In other words, is the first proportion (p1) the same as (p2)? What formula, from this weekâ€™s Notations and Symbols, would be applicable in the hypothesis test? (Notice you are not doing a hypothesis test â€“ you are saying which formula applies).