2/11/2021 Sophia :: Welcome
Score 23/24
You passed this Milestone
23 questions were answered correctly.
UNIT 5 — MILESTONE 5
1 question was answered incorrectly.
1
One condition for performing a hypothesis test is that the observations are independent. Marta is going to take a
sample from a population of 600 students.
How many students will Marta have to sample without replacement to treat the observations as
independent?
120
300
60
540
RATIONALE
In general we want about 10% or less to still assume independence.
So size = 0.1*N = 0.1(600) = 60
A sample of 60 or less would be sufficient.
CONCEPT
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 1/21
,2/11/2021 Sophia :: Welcome
Sampling With or Without Replacement
2
The table below shows the results of a customer satisfaction survey at a particular restaurant broken down by
males and females.
Male Female
Extremely Satisfied 25 7
Satisfied 21 13
Neutral 13 16
Dissatisfied 9 14
Extremely Dissatisfied 2 5
Assuming all 5 choices are equally likely, select the observed and expected frequency for male customers
that are dissatisfied.
Observed: 14
Expected: 9
Observed: 9
Expected: 12.5
Observed: 9
Expected: 25
Observed: 9
Expected: 14
RATIONALE
If we simply go to the chart then we can directly see the observed frequency for male customers who are
dissatisfied is 9.
To find the expected frequency, we need to find the number of
occurrences if the null hypothesis is true, which in this case, was that the five options are equally likely, or if the
five options were all evenly distributed.
First, add up all the options in the Male column:
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 2/21
, 2/11/2021 Sophia :: Welcome
If each of these five options were evenly distributed among the 70 males, we would need to divide the total
evenly between the five options:
This means we would expect 14 men to be extremely satisfied, satisfied, neutral, dissatisfied, and extremely
dissatisfied.
CONCEPT
Chi-Square Statistic
3
Henri has calculated a z-test statistic of -2.73.
What is the p-value of the test statistic? Answer choices are rounded to the thousandths place.
0.006
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 3/21
Score 23/24
You passed this Milestone
23 questions were answered correctly.
UNIT 5 — MILESTONE 5
1 question was answered incorrectly.
1
One condition for performing a hypothesis test is that the observations are independent. Marta is going to take a
sample from a population of 600 students.
How many students will Marta have to sample without replacement to treat the observations as
independent?
120
300
60
540
RATIONALE
In general we want about 10% or less to still assume independence.
So size = 0.1*N = 0.1(600) = 60
A sample of 60 or less would be sufficient.
CONCEPT
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 1/21
,2/11/2021 Sophia :: Welcome
Sampling With or Without Replacement
2
The table below shows the results of a customer satisfaction survey at a particular restaurant broken down by
males and females.
Male Female
Extremely Satisfied 25 7
Satisfied 21 13
Neutral 13 16
Dissatisfied 9 14
Extremely Dissatisfied 2 5
Assuming all 5 choices are equally likely, select the observed and expected frequency for male customers
that are dissatisfied.
Observed: 14
Expected: 9
Observed: 9
Expected: 12.5
Observed: 9
Expected: 25
Observed: 9
Expected: 14
RATIONALE
If we simply go to the chart then we can directly see the observed frequency for male customers who are
dissatisfied is 9.
To find the expected frequency, we need to find the number of
occurrences if the null hypothesis is true, which in this case, was that the five options are equally likely, or if the
five options were all evenly distributed.
First, add up all the options in the Male column:
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 2/21
, 2/11/2021 Sophia :: Welcome
If each of these five options were evenly distributed among the 70 males, we would need to divide the total
evenly between the five options:
This means we would expect 14 men to be extremely satisfied, satisfied, neutral, dissatisfied, and extremely
dissatisfied.
CONCEPT
Chi-Square Statistic
3
Henri has calculated a z-test statistic of -2.73.
What is the p-value of the test statistic? Answer choices are rounded to the thousandths place.
0.006
https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/7859865 3/21
