STAT 121 Exam 2025 Practice Questions Verified
Answers
The value of a parameter will only change if
the population changes
What is the random variable of the sampling distribution of x̄ ?
the sample mean
Which one of the following does NOT have variability?
a) a parameter
b) data
c) a statistic
d) a random variable
e) a quantitative response variable
a) a parameter
Which one of the following is NOT a parameter?
a) the mean of the measurements on all the individuals in a population.
b) the proportion of a population that have a certain characteristic.
c) the standard deviation of an entire population.
d) the proportion in a survey that favor a certain opinion.
d) the proportion in a survey that favor a certain opinion.
Fill in the blank: Central Limit Theorem allows us to compute probabilities on ___________
using the standard Normal table provided the sample size of the random sample is
sufficiently large.
x̄
, The sampling distribution of a statistic has all of the following except a) shape.
b) center.
c) spread.
d) correlation.
d) correlation.
Which one of the following measures the variability of a statistic?
a) the standard deviation of the data.
b) the standard deviation of the sampling distribution for the statistic.
c) the total sum of squared deviations of the observations about the mean.
d) thenumberofstandarddeviationsthatastatisticvaluediffersfromtheparameter
value.
b) the standard deviation of the sampling distribution for the statistic.
The theoretical sampling distribution of a statistic consists of
the values of a statistic from all possible samples.
The standard deviation of the sampling distribution of x̄ measures
the variability of the sample mean values about the parameter, μ.
A random sample of size 10 was taken from a population. The sample has a standard
deviation of zero. Which of the following statements must be true.
a) The population has a standard deviation of zero.
b) The sample mean is greater than the sample median.
c) The ten data points in the sample are all equal in numerical value.
d) The sample size is too small to compute standard deviation.
c) The ten data points in the sample are all equal in numerical value.
For the theoretical sampling distribution of x̄ created by taking all possible samples of size 16
from a very left skewed population with μ = 22 and σ = 4, the mean of this sampling
distribution
Answers
The value of a parameter will only change if
the population changes
What is the random variable of the sampling distribution of x̄ ?
the sample mean
Which one of the following does NOT have variability?
a) a parameter
b) data
c) a statistic
d) a random variable
e) a quantitative response variable
a) a parameter
Which one of the following is NOT a parameter?
a) the mean of the measurements on all the individuals in a population.
b) the proportion of a population that have a certain characteristic.
c) the standard deviation of an entire population.
d) the proportion in a survey that favor a certain opinion.
d) the proportion in a survey that favor a certain opinion.
Fill in the blank: Central Limit Theorem allows us to compute probabilities on ___________
using the standard Normal table provided the sample size of the random sample is
sufficiently large.
x̄
, The sampling distribution of a statistic has all of the following except a) shape.
b) center.
c) spread.
d) correlation.
d) correlation.
Which one of the following measures the variability of a statistic?
a) the standard deviation of the data.
b) the standard deviation of the sampling distribution for the statistic.
c) the total sum of squared deviations of the observations about the mean.
d) thenumberofstandarddeviationsthatastatisticvaluediffersfromtheparameter
value.
b) the standard deviation of the sampling distribution for the statistic.
The theoretical sampling distribution of a statistic consists of
the values of a statistic from all possible samples.
The standard deviation of the sampling distribution of x̄ measures
the variability of the sample mean values about the parameter, μ.
A random sample of size 10 was taken from a population. The sample has a standard
deviation of zero. Which of the following statements must be true.
a) The population has a standard deviation of zero.
b) The sample mean is greater than the sample median.
c) The ten data points in the sample are all equal in numerical value.
d) The sample size is too small to compute standard deviation.
c) The ten data points in the sample are all equal in numerical value.
For the theoretical sampling distribution of x̄ created by taking all possible samples of size 16
from a very left skewed population with μ = 22 and σ = 4, the mean of this sampling
distribution
