Multiple Choice
Identify the
choice that best completes the statement or answers the question.
|
|
|
1.
|
The graph at the right show the
frequency distribution of a population with a population mean of 4 and a population standard
deviation of 2.5.
If samples of size 25 (n =25) were taken from the population what
would be the mean of the sample means  ?
| | | |
|
|
|
2.
|
The graph at the right show the
frequency distribution of a population with a population mean of 2.5 and a population standard
deviation of 3.
If samples of size 36 (n =36) were taken from the population
what would be the standard deviation of the sample means  ?
| | | |
|
|
|
3.
|
The graph at the right show the
frequency distribution of a population with a population mean of 2.5 and a population standard
deviation of 3.
If samples of size 25 (n =25) were taken from the population which
graph would most likely be a good representation of the distribution of the sample means?
| | | |
|
|
|
4.
|
A high school student spends an
average of 6 hours ( ) on their phone a day with a standard deviation
of 2.5 hours ( ).
If samples of size 16 (n =16)
were taken from the population what would be the mean of the sample means  ?
| | | |
|
|
|
5.
|
Use the central limit theorem if
possible. For a sample of n = 36, find the probability of a sample mean being
greater than 43 given  and  .
The population is also normally distributed.
| | | |
(Hint: First determine  and  and use those values to find  )
a. | 0.3085 | c. | 0.5332 | b. | 0.4668 | d. | 0.6915 |
|
|
|
6.
|
Use the central limit theorem if
possible. For a sample of n = 9, find the probability of a sample mean being less than
7 given  and  . The population is
not normally distributed.
| | | |
a. | 0.1587 | c. | 0.8413 | b. | 0.3694 | d. | Cannot be determined because the sample size is
too small. |
|
|
|
7.
|
At a restaurant near the high
school, the restaurant manager has determined that each customer on average spends $9.10 ( ) with a standard deviation of $3.00 ( ). The customer data was
normally distributed.
A group of 4 friends (n = 4) went to the restaurant
together and one of the friends bought lunch for entire group. What is the probability that the total
bill will be more than $40?
(Hint: This suggests finding the
probability that the sample mean would be greater than $10.00.)
| | | |
a. | 12.8% | c. | 38.2% | b. | 27.4% | d. | 42.1% |
|
|
|
8.
|
The length of pregnancies are
normally distributed with a mean of 268 days ( ) and a standard
deviation of 15 days ( ).
A group of 36 pregnant women
(n = 36) were in a parenting class together. What is the probability that
the average pregnancy for the women lasted longer than 270 days?
| | | |
a. | 21.2% | c. | 55.2% | b. | 28.8% | d. | 78.8% |
|