MATH 225N Statistics
Week 8 Final Exam Question 1
1/1 points
A fitness center claims that the mean amount of time that a person spends at
... [Show More] the gym per visit
is 33 minutes. Identify the null hypothesis, H0, and the alternative hypothesis, Ha, in terms of
th e parameter μ.
That is correct!
H0: μ≠33; Ha: μ=33
H0: μ=33; Ha: μ≠33
H0: μ≥33; Ha: μ<33
H0: μ≤33; Ha: μ>33
Answer Explanation
Correct answer:
H0: μ=33; Ha: μ≠33
Let the parameter μ be used to represent the mean. The null hypothesis is always stated with
some form of equality: equal (=), greater than or equal to (≥), or less than or equal to (≤).
Therefore, in this case, the null hypothesis H0 is μ=33. The alternative hypothesis is
contradictory to the null hypothesis, so Ha is μ≠33.
Question 2
1/1 points
The answer choices below represent different hypothesis tests. Which of the choices are righttai
led tests? Select all correct answers.
That is correct!
•
H0:X≥17.1, Ha:X<17.1
•
•
H0:X=14.4, Ha:X≠14.4
•
•
H0:X≤3.8, Ha:X>3.8
•
•
H0:X≤7.4, Ha:X>7.4
•
•
H0:X=3.3, Ha:X≠3.3
•
Answer Explanation
Correct answer:
H0:X≤3.8, Ha:X>3.8
H0:X≤7.4, Ha:X>7.4
Remember the forms of the hypothesis tests.
• Right-tailed: H0:X≤X0, Ha:X>X0.
• Left-tailed: H0:X≥X0, Ha:X7.4
• H0:X≤3.8, Ha:X>3.8
Question 3
1/1 points
Find the Type II error given that the null hypothesis, H0, is: a building inspector claims that no
more than 15% of structures in the county were built without permits.
That is correct!
The building inspector thinks that no more than 15% of the structures in the county were
built without permits when, in fact, no more than 15% of the structures really were built
without permits.
The building inspector thinks that more than 15% of the structures in the county were built
without permits when, in fact, more than 15% of the structures really were built without
permits.
The building inspector thinks that more than 15% of the structures in the county were
built without permits when, in fact, at most 15% of the structures were built without
permits.
The building inspector thinks that no more than 15% of the structures in the county were
built without permits when, in fact, more than 15% of the structures were built without
permits.
Answer Explanation
Correct answer:
The building inspector thinks that no more than 15% of the structures in the county were
built without permits when, in fact, more than 15% of the structures were built without
permits.
A Type II error is the decision not to reject the null hypothesis when, in fact, it is false. In this
case, the Type II error is when the building inspector thinks that no more than 15% of the
structures were built without permits when, in fact, more than 15% of the structures were
built without permits. [Show Less]