QUESTION 1
·
1/1 POINTS
The answer choices below represent different hypothesis tests. Which of the choices
are left-tailed tests? Select all correct answers.
That is correct!
•
H0:X=17.3, Ha:X≠17.3
•
•
H0:X=19.7, Ha:X<19.7
•
•
H0:X=11.2, Ha:X<11.2
•
•
H0:X=13.2, Ha:X≠13.2
•
•
H0:X=17.8, Ha:X>17.8
•
Answer Explanation
Correct answer:
H0:X=19.7, Ha:X<19.7
, H0:X=11.2, Ha:X<11.2
Remember the forms of the hypothesis tests.
• Right-tailed: H0:X=X0, Ha:X>X0.
• Left-tailed: H0:X=X0, Ha:X<X0.
• Two-tailed: H0:X=X0, Ha:X≠X0.
So in this case, the left-tailed tests are:
• H0:X=11.2, Ha:X<11.2
• H0:X=19.7, Ha:X<19.7
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 2
·
1/1 POINTS
Clarence, a typist, has a sample typing speed mean of 75.2 words per minute
from 18 trials. Clarence still claims that his average typing speed is 84 words per
minute, and the low average can be attributed to chance. At the 5% significance level,
does the data provide sufficient evidence to conclude that Clarence's mean typing
speed is less than 84 words per minute? Given the sample data below, accept or reject
the hypothesis.
• H0:μ=84 words per minute; Ha:μ<84 words per minute
• α=0.05 (significance level)
• z0=−2.7
• p=0.0035
That is correct!
, Do not reject the null hypothesis because the value of z is negative.
Do not reject the null hypothesis because the p-value 0.0035 is less than the
significance level α=0.05.
Reject the null hypothesis because the p-value 0.0035 is less than the significance
level α=0.05.
Reject the null hypothesis because |−2.7|>0.05.
Do not reject the null hypothesis because |−2.7|>0.05.
Answer Explanation
Correct answer:
Reject the null hypothesis because the p-value 0.0035 is less than the significance
level α=0.05.
In making the decision to reject or not reject H0, if α>p-value, reject H0 because the
results of the sample data are significant. There is sufficient evidence to conclude
that H0 is an incorrect belief and that the alternative hypothesis, Ha, may be correct.
If α≤p-value, do not reject H0. The results of the sample data are not significant, so
there is not sufficient evidence to conclude that the alternative hypothesis, Ha, may be
correct. In this case, α=0.05 is greater than p=0.0035, so the decision is to reject the
null hypothesis.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
·
1/1 POINTS
The answer choices below represent different hypothesis tests. Which of the choices
are left-tailed tests? Select all correct answers.
That is correct!
•
H0:X=17.3, Ha:X≠17.3
•
•
H0:X=19.7, Ha:X<19.7
•
•
H0:X=11.2, Ha:X<11.2
•
•
H0:X=13.2, Ha:X≠13.2
•
•
H0:X=17.8, Ha:X>17.8
•
Answer Explanation
Correct answer:
H0:X=19.7, Ha:X<19.7
, H0:X=11.2, Ha:X<11.2
Remember the forms of the hypothesis tests.
• Right-tailed: H0:X=X0, Ha:X>X0.
• Left-tailed: H0:X=X0, Ha:X<X0.
• Two-tailed: H0:X=X0, Ha:X≠X0.
So in this case, the left-tailed tests are:
• H0:X=11.2, Ha:X<11.2
• H0:X=19.7, Ha:X<19.7
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 2
·
1/1 POINTS
Clarence, a typist, has a sample typing speed mean of 75.2 words per minute
from 18 trials. Clarence still claims that his average typing speed is 84 words per
minute, and the low average can be attributed to chance. At the 5% significance level,
does the data provide sufficient evidence to conclude that Clarence's mean typing
speed is less than 84 words per minute? Given the sample data below, accept or reject
the hypothesis.
• H0:μ=84 words per minute; Ha:μ<84 words per minute
• α=0.05 (significance level)
• z0=−2.7
• p=0.0035
That is correct!
, Do not reject the null hypothesis because the value of z is negative.
Do not reject the null hypothesis because the p-value 0.0035 is less than the
significance level α=0.05.
Reject the null hypothesis because the p-value 0.0035 is less than the significance
level α=0.05.
Reject the null hypothesis because |−2.7|>0.05.
Do not reject the null hypothesis because |−2.7|>0.05.
Answer Explanation
Correct answer:
Reject the null hypothesis because the p-value 0.0035 is less than the significance
level α=0.05.
In making the decision to reject or not reject H0, if α>p-value, reject H0 because the
results of the sample data are significant. There is sufficient evidence to conclude
that H0 is an incorrect belief and that the alternative hypothesis, Ha, may be correct.
If α≤p-value, do not reject H0. The results of the sample data are not significant, so
there is not sufficient evidence to conclude that the alternative hypothesis, Ha, may be
correct. In this case, α=0.05 is greater than p=0.0035, so the decision is to reject the
null hypothesis.
FEEDBACK
•
•
•
•
Content attribution- Opens a dialog
QUESTION 3
·
1/1 POINTS
