# mat201 case 5

By submitting this assignment, you affirm that it contains all original work, and that you are familiar with Trident University’s Academic Integrity policy in the Trident Policy Handbook. You affirm that you have not engaged in direct duplication, copy/pasting, sharing assignments, collaboration with others, contract cheating and/or obtaining answers online, paraphrasing, or submitting/facilitating the submission of prior work. Work found to be unoriginal and in violation of this policy is subject to consequences such as a failing grade on the assignment, a failing grade in the course, and/or elevated academic sanctions. You affirm that the assignment was completed individually, and all work presented is your own.

Problems need to include all required steps and answer(s) for full credit. All answers need to be reduced to lowest terms where possible.

Answer the following problems showing your work and explaining (or analyzing) your results.

- Explain Type I and Type II errors. Use an example if needed.
- Explain a one-tailed and two-tailed test. Use an example if needed.
- Define the following terms in your own words.

- Null hypothesis
- P-value
- Critical value
- Statistically significant

_{o}and the alternative hypothesis H

_{a}.

- Write the research hypothesis and the null hypothesis.
- Then construct a table like the one below, displaying the outcomes that would constitute Type I and Type II error.
- Write a paragraph explaining which error would be more severe, and why.

- Cough-a-Lot children’s cough syrup is supposed to contain 6 ounces of medicine per bottle. However since the filling machine is not always precise, there can be variation from bottle to bottle. The amounts in the bottles are normally distributed with σ = 0.3 ounces. A quality assurance inspector measures 10 bottles and finds the following (in ounces):

5.95 | 6.10 | 5.98 | 6.01 | 6.25 | 5.85 | 5.91 | 6.05 | 5.88 | 5.91 |

Are the results enough evidence to conclude that the bottles are not filled adequately at the labeled amount of 6 ounces per bottle?

- State the hypothesis you will test.
- Calculate the test statistic.
- Find the P-value.
- What is the conclusion?

- Calculate a Z score when X = 20, μ = 17, and σ = 3.4.
- Using a standard normal probabilities table, interpret the results for the Z score in Problem 7.
- Your babysitter claims that she is underpaid given the current market. Her hourly wage is $12 per hour. You do some research and discover that the average wage in your area is $14 per hour with a standard deviation of 1.9. Calculate the Z score and use the table to find the standard normal probability. Based on your findings, should you give her a raise? Explain your reasoning as to why or why not.
- Tutor O-Rama claims that their services will raise student SAT math scores at least 50 points. The average score on the math portion of the SAT is μ=350 and σ=35. The 100 students who completed the tutoring program had an average score of 385 points.
- Is the students’ average score of 385 points significant at the 5% and 1% levels to support Tutor O-Rama’s claim of at least a 50-point increase in the SAT score?
- Is the Tutor O-Rama students’ average score of 385 points significantly different at the 5% and 1% levels from the average score of 350 points on the math portion of the SAT? What conclusion can you make, based on your results, about the effectiveness of Tutor O-Rama’s tutoring?