A physician wants to see if there was a difference in the average smokers' daily cigarette
consumption after wearing a nicotine patch. The physician set up a study to track daily smoking
consumption. In the study, the patients were given a placebo patch that did not contain nicotine
for 4 weeks, then a nicotine patch for the following 4 weeks. Test to see if there was a difference
in the average smoker's daily cigarette consumption using α = 0.01. The hypotheses are:
H0 : μD = 0
H1 : μD ≠ 0
t-Test: Paired Two Sample for Means
Placebo Nicotine
Mean 16.75 10.3125
Variance 64.46667 33.29583
Observations 16 16
Pearson Correlation 0.6105
Hypothesized Mean
Difference 0
df 15
t Stat 4.0119
P(T<=t) one-tail 0.0006
t Critical one-tail 2.6025
P(T<=t) two-tail 0.0011
t Critical two-tail 2.9467
What is the correct decision?
Question options:
Accept H1
Do not reject H0
Reject H0
Reject H1
, Accept H0
Hide Feedback
The p-value for a two tailed test is 0.0011. This is given to you in the output. No calculations are needed.
point
A manager wants to see if it is worth going back for an MBA degree. They randomly
sample 18 managers' salaries before and after undertaking a MBA degree and record their
salaries in thousands of dollars. Assume Salaries are normally distributed. Test the claim that the
MBA degree, on average, increases a manager's salary. Use a 10% level of significance.
t-Test: Paired Two Sample for Means
New Old
Salary Salary
Mean 59.82778 52.66667
Variance 175.5551 112.7012
Observations 18 18
Pearson Correlation 0.7464
Hypothesized Mean
Difference 0
df 17
t Stat 3.4340
P(T<=t) one-tail 0.0016
t Critical one-tail 1.3334
P(T<=t) two-tail 0.0033
t Critical two-tail 1.7396
The hypotheses for this problem are:
H0: μD = 0
H1: μD > 0
What is the correct p-value?
Question options:
, 0.0016
-1.3334
-3.4340
0.0033
0.7464
Hide Feedback
No calculations are needed. The answer is given to you in the output.
P(T<=t) one-tail 0.0016
point
Two competing toothpaste brands both claim to produce the best toothpaste for
whitening. A dentist randomly samples 48 patients that use Brand A (Group 1) and finds 30 of
them are satisfied with the whitening results of the toothpaste. She then randomly samples 45
patients that use Brand B (Group 2) and finds 33 of them are satisfied with the whitening results
of the toothpaste. Construct a 99% confidence interval for the difference in proportions and use it
to decide if there is a significant difference in the satisfaction level of patients.
Enter the confidence interval - round to 3 decimal places.
___-0.356___
< p1 - p2 <
___0.139___
Hide Feedback
Z-Critical Value =NORM.S.INV(.995) = 2.575
LL = (.625-.7333) - 2.575*
.625∗.37548+.7333∗.266745−−−−−−−−−−−−−−−−−−−−−−√{"version":"1.1","math":"\displaystyle \sqrt{
UL = (.625-.7333) + 2.575*
.625∗.37548+.7333∗.266745−−−−−−−−−−−−−−−−−−−−−−√{"version":"1.1","math":"\displaystyle \sqrt{
Question 4
In a 2-sample z-test for two proportions, you find the following:
consumption after wearing a nicotine patch. The physician set up a study to track daily smoking
consumption. In the study, the patients were given a placebo patch that did not contain nicotine
for 4 weeks, then a nicotine patch for the following 4 weeks. Test to see if there was a difference
in the average smoker's daily cigarette consumption using α = 0.01. The hypotheses are:
H0 : μD = 0
H1 : μD ≠ 0
t-Test: Paired Two Sample for Means
Placebo Nicotine
Mean 16.75 10.3125
Variance 64.46667 33.29583
Observations 16 16
Pearson Correlation 0.6105
Hypothesized Mean
Difference 0
df 15
t Stat 4.0119
P(T<=t) one-tail 0.0006
t Critical one-tail 2.6025
P(T<=t) two-tail 0.0011
t Critical two-tail 2.9467
What is the correct decision?
Question options:
Accept H1
Do not reject H0
Reject H0
Reject H1
, Accept H0
Hide Feedback
The p-value for a two tailed test is 0.0011. This is given to you in the output. No calculations are needed.
point
A manager wants to see if it is worth going back for an MBA degree. They randomly
sample 18 managers' salaries before and after undertaking a MBA degree and record their
salaries in thousands of dollars. Assume Salaries are normally distributed. Test the claim that the
MBA degree, on average, increases a manager's salary. Use a 10% level of significance.
t-Test: Paired Two Sample for Means
New Old
Salary Salary
Mean 59.82778 52.66667
Variance 175.5551 112.7012
Observations 18 18
Pearson Correlation 0.7464
Hypothesized Mean
Difference 0
df 17
t Stat 3.4340
P(T<=t) one-tail 0.0016
t Critical one-tail 1.3334
P(T<=t) two-tail 0.0033
t Critical two-tail 1.7396
The hypotheses for this problem are:
H0: μD = 0
H1: μD > 0
What is the correct p-value?
Question options:
, 0.0016
-1.3334
-3.4340
0.0033
0.7464
Hide Feedback
No calculations are needed. The answer is given to you in the output.
P(T<=t) one-tail 0.0016
point
Two competing toothpaste brands both claim to produce the best toothpaste for
whitening. A dentist randomly samples 48 patients that use Brand A (Group 1) and finds 30 of
them are satisfied with the whitening results of the toothpaste. She then randomly samples 45
patients that use Brand B (Group 2) and finds 33 of them are satisfied with the whitening results
of the toothpaste. Construct a 99% confidence interval for the difference in proportions and use it
to decide if there is a significant difference in the satisfaction level of patients.
Enter the confidence interval - round to 3 decimal places.
___-0.356___
< p1 - p2 <
___0.139___
Hide Feedback
Z-Critical Value =NORM.S.INV(.995) = 2.575
LL = (.625-.7333) - 2.575*
.625∗.37548+.7333∗.266745−−−−−−−−−−−−−−−−−−−−−−√{"version":"1.1","math":"\displaystyle \sqrt{
UL = (.625-.7333) + 2.575*
.625∗.37548+.7333∗.266745−−−−−−−−−−−−−−−−−−−−−−√{"version":"1.1","math":"\displaystyle \sqrt{
Question 4
In a 2-sample z-test for two proportions, you find the following:
