SAMPLING DISTRIBUTIONS CHECKPOINT 2
Step 1 of 1
Question 1 of 5 Points: 10
The length of human pregnancy is known to have mean length of 268
days. A random sample of 64 pregnant women was selected and it was
found that the average pregnancy length in that sample was 266 days.
Which of the following is a true statement about this scenario?
If a different random sample of 64 pregnant women were selected, the average pregnancy
length in that sample would have to be also 266 days.
Both 268 and 266 are parameters
Both 268 and 266 are statistics
268 is a parameter and 266 is a statistic
The recorded sample average of 266 days is clearly a mistake. It must be 268 days just like the
population mean.
Question 2 of 5 Points: 10
Which of the following statements about the sampling distribution of the
sample mean, x-bar, is not true?
The sampling distribution is normal regardless of the shape of the population distribution, as
long as the sample size, n, is large enough.
The sampling distribution is normal regardless of the sample size, as long as the population
distribution is normal.
The sampling distribution's mean is the same as the population mean.
The sampling distribution's standard deviation is smaller than the population standard
deviation.
All of the above statements are true.
The next two questions refer to the following information:
, To estimate the mean number of daily study hours in the population of all
the students at a large public university, a researcher plans to randomly
sample students from this population and then calculate the average
number of daily study hours for the sample (x-bar). Pictured below (in
scrambled order) are three histograms:
The distribution of study hours in the population of all students in
the university
The sampling distribution x-bar when samples of size n=5 are chosen
from the population.
The sampling distribution x-bar when samples of size n=30 are
chosen from the population.
, Question 3 of 5 Points: 10
Which of the following 6 possible orderings of the three histograms
represents the sequence:
Population distribution
Sampling distribution of x-bar for sample size n = 5
Sampling distribution of x-bar for sample size n = 30?
Step 1 of 1
Question 1 of 5 Points: 10
The length of human pregnancy is known to have mean length of 268
days. A random sample of 64 pregnant women was selected and it was
found that the average pregnancy length in that sample was 266 days.
Which of the following is a true statement about this scenario?
If a different random sample of 64 pregnant women were selected, the average pregnancy
length in that sample would have to be also 266 days.
Both 268 and 266 are parameters
Both 268 and 266 are statistics
268 is a parameter and 266 is a statistic
The recorded sample average of 266 days is clearly a mistake. It must be 268 days just like the
population mean.
Question 2 of 5 Points: 10
Which of the following statements about the sampling distribution of the
sample mean, x-bar, is not true?
The sampling distribution is normal regardless of the shape of the population distribution, as
long as the sample size, n, is large enough.
The sampling distribution is normal regardless of the sample size, as long as the population
distribution is normal.
The sampling distribution's mean is the same as the population mean.
The sampling distribution's standard deviation is smaller than the population standard
deviation.
All of the above statements are true.
The next two questions refer to the following information:
, To estimate the mean number of daily study hours in the population of all
the students at a large public university, a researcher plans to randomly
sample students from this population and then calculate the average
number of daily study hours for the sample (x-bar). Pictured below (in
scrambled order) are three histograms:
The distribution of study hours in the population of all students in
the university
The sampling distribution x-bar when samples of size n=5 are chosen
from the population.
The sampling distribution x-bar when samples of size n=30 are
chosen from the population.
, Question 3 of 5 Points: 10
Which of the following 6 possible orderings of the three histograms
represents the sequence:
Population distribution
Sampling distribution of x-bar for sample size n = 5
Sampling distribution of x-bar for sample size n = 30?
