ECO 391 - EXAM #1 | Latest study set |
Questions and Answers
The variance of a sample or a population cannot be ________.
a.) negative
b.) calculated
c.) zero
d.) less than 1 - ANSW-a.) negative
The median of a sample will always equal the ________.
a.) mode
b.) mean
c.) 50th percentile
d.) all of the ANSWers are correct - ANSW-c.) 50th percentile
A researcher has collected the following sample data.
5, 12, 6, 8, 5, 6, 7, 5, 12, 4
The median is ________.
a.) 5
b.) 6
c.) 7
d.) 8 - ANSW-b.) 6
Step 1: Move to ascending order.
4, 5, 5, 5, 6, 6, 7, 8, 12, 12
Step 2: Since there is an even amount of numbers, find the average of the two middle values.
(6 + 6) / 2 = 6
The Boom Company has recently decided to raise the salaries of all employees by 10%. Which of the
following is (are) expected to be affected by this raise?
a.) mean and mode only
b.) mean and median only
c.) mode and median only
d.) mean, median, and mode - ANSW-d.) mean, median, and mode
If a data set has an even number of observations, the median ________.
a.) cannot be determined
b.) is the observation recorded most often
c.) must be equal to the mean
d.) is the average value of the two middle items when all items are arranged in ascending order - ANSW-
d.) is the average value of the two middle items when all items are in ascending order
, The median is defined as the ________.
a.) middle point in a data set
b.) geometric average of a data set
c.) range of a data set
d.) most common value of a data set - ANSW-a.) middle point in a data set
The mode is defined as the ________.
a.) middle point in a data set
b.) geometric average of a data set
c.) arithmetic average of a data set
d.) most frequent value in a data set - ANSW-d.) most frequent value in a data set
Which of the following is most influenced by outliers?
An outlier is an observation that lies an abnormal distance from other values in a random sample from a
population.
a.) mode
b.) median
c.) 75th percentile
d.) range - ANSW-d.) range
Is it possible to have no mode in a data set?
a.) yes, if two observations occur twice
b.) no, unless there is an odd number of observations
c.) no, if the data is nonempty there is a mode
d.) yes, if no observations occur more than once - ANSW-d.) yes, if no observations occur more than
once
The owner of a company has recently decided to raise the salary of one employee, who was already
making the highest salary, by 20%. Which of the following is (are) expected to be affected by this raise?
a.) mean only
b.) median only
c.) mean and median only
d.) mean, median, and mode - ANSW-a.) mean only
Raising the highest value in a data set will change only the mean of the sample. The median and the
mode will still be the same in the dataset.
What is (are) the most widely used measure(s) of dispersion?
a.) range
b.) interquartile range
c.) variance and standard deviation
d.) covariance and the correlation coefficient - ANSW-c.) variance and the standard deviation
What is the relationship between the variance and the standard deviation?
a.) the standard deviation is the absolute value of the variance.
b.) the variance is the absolute value of the standard deviation
Questions and Answers
The variance of a sample or a population cannot be ________.
a.) negative
b.) calculated
c.) zero
d.) less than 1 - ANSW-a.) negative
The median of a sample will always equal the ________.
a.) mode
b.) mean
c.) 50th percentile
d.) all of the ANSWers are correct - ANSW-c.) 50th percentile
A researcher has collected the following sample data.
5, 12, 6, 8, 5, 6, 7, 5, 12, 4
The median is ________.
a.) 5
b.) 6
c.) 7
d.) 8 - ANSW-b.) 6
Step 1: Move to ascending order.
4, 5, 5, 5, 6, 6, 7, 8, 12, 12
Step 2: Since there is an even amount of numbers, find the average of the two middle values.
(6 + 6) / 2 = 6
The Boom Company has recently decided to raise the salaries of all employees by 10%. Which of the
following is (are) expected to be affected by this raise?
a.) mean and mode only
b.) mean and median only
c.) mode and median only
d.) mean, median, and mode - ANSW-d.) mean, median, and mode
If a data set has an even number of observations, the median ________.
a.) cannot be determined
b.) is the observation recorded most often
c.) must be equal to the mean
d.) is the average value of the two middle items when all items are arranged in ascending order - ANSW-
d.) is the average value of the two middle items when all items are in ascending order
, The median is defined as the ________.
a.) middle point in a data set
b.) geometric average of a data set
c.) range of a data set
d.) most common value of a data set - ANSW-a.) middle point in a data set
The mode is defined as the ________.
a.) middle point in a data set
b.) geometric average of a data set
c.) arithmetic average of a data set
d.) most frequent value in a data set - ANSW-d.) most frequent value in a data set
Which of the following is most influenced by outliers?
An outlier is an observation that lies an abnormal distance from other values in a random sample from a
population.
a.) mode
b.) median
c.) 75th percentile
d.) range - ANSW-d.) range
Is it possible to have no mode in a data set?
a.) yes, if two observations occur twice
b.) no, unless there is an odd number of observations
c.) no, if the data is nonempty there is a mode
d.) yes, if no observations occur more than once - ANSW-d.) yes, if no observations occur more than
once
The owner of a company has recently decided to raise the salary of one employee, who was already
making the highest salary, by 20%. Which of the following is (are) expected to be affected by this raise?
a.) mean only
b.) median only
c.) mean and median only
d.) mean, median, and mode - ANSW-a.) mean only
Raising the highest value in a data set will change only the mean of the sample. The median and the
mode will still be the same in the dataset.
What is (are) the most widely used measure(s) of dispersion?
a.) range
b.) interquartile range
c.) variance and standard deviation
d.) covariance and the correlation coefficient - ANSW-c.) variance and the standard deviation
What is the relationship between the variance and the standard deviation?
a.) the standard deviation is the absolute value of the variance.
b.) the variance is the absolute value of the standard deviation
