In Problems 15–22, (a) determine the null and alternative hypotheses, (b) explain what it would mean to make a Type I error, and (c) explain what it would mean to make a Type II error . 15. Complete College For students who first enrolled in two-year public institutions in fall 2007, the proportion who earned a bachelor’s degree within six years was 0.399. The president of Joliet Junior College believes that the proportion of students who enroll in her institution have a higher completion rate.
In Problems 15–22, (a) determine the null and alternative hypotheses, (b) explain what it would mean to make a Type I error, and (c) explain what it would mean to make a Type II error . 15. Complete College For students who first enrolled in two-year public institutions in fall 2007, the proportion who earned a bachelor’s degree within six years was 0.399. The president of Joliet Junior College believes that the proportion of students who enroll in her institution have a higher completion rate.
In Problems 15–22, (a) determine the null and alternative hypotheses, (b) explain what it would mean to make a Type I error, and (c) explain what it would mean to make a Type II error.
15. Complete College For students who first enrolled in two-year public institutions in fall 2007, the proportion who earned a bachelor’s degree within six years was 0.399. The president of Joliet Junior College believes that the proportion of students who enroll in her institution have a higher completion rate.
A paint manufacturer advertises that one gallon of its paint will cover 400 square feet of an interior wall. Some local painters suspect the average coverage is considerably less and decide to conduct an experiment to find out. Which of the following are the correct null and alternative hypotheses to be tested?
A construction company has a bid on two large construction projects. The president believes that the chances of winning the first contract is 55% and the chances of winning the second contract is 30% and that winning either contract is independent of winning the other. What are the chances the company will not win either contract?
Spelling mistakes in a text are either “nonword errors” or “word errors.” A nonword error produces a string of letters that is not a word, such as “the” typed as “teh.” Word errors produce the wrong word, such as “loose” typed as “lose.” Nonword errors make up 25% of all errors. A human proofreader will catch 80% of nonword errors and 50% of…
PROBLEM:
Parker et. al in 2004 stated that a combination of selenium and folic acid is just as effective as Prednisone in anti-inflammatory property. On the right are the results of the reduction of the number of patients with allergies during the study period. At 90% confidence level, test the claim that selenium and folic acid has similar anti-inflammatory property as Prednisone by using the traditional method of hypothesis testing.
QUESTIONS:
1. Give the null and alt. hypothesis in symbols.
2. Give the null and alt. hypothesis in words.
3. Identify the tail of the test.
4. Determine the critical value or p-value ().
5. Identify what test to be used and explain why.
6. Make the decision using specific evidence.
7. Summarize the results for the study.
Look at the table that lists SAT scores before and after a sample of five students took a prep class and state the null and alternate hypotheses to test the effectiveness of the course in improving SAT scores.
Student
1
2
3
4
5
SAT score before class
700
840
830
860
600
SAT score after class
720
840
820
900
700
Basic Business Statistics, Student Value Edition (13th Edition)
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Hypothesis Testing - Solving Problems With Proportions; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=76VruarGn2Q;License: Standard YouTube License, CC-BY
Hypothesis Testing and Confidence Intervals (FRM Part 1 – Book 2 – Chapter 5); Author: Analystprep;https://www.youtube.com/watch?v=vth3yZIUlGQ;License: Standard YouTube License, CC-BY