Statistics Final Exam Questions With Correct Solutions.
How is a sample related to a population? - accurate answers-A sample is a
subset of a population.
Why is a sample used more often than a population? - accurate answers-It is
usually impossible to count the entire population
What is the difference between a parameter and a statistic? - accurate
answers-A parameter is a numerical description of a population characteristic.
A statistic is a numerical description of a sample characteristic.
What are the two main divisions of statistics? - accurate answers-descriptive
and inferential
Determine whether the data set is a population of a sample.
The carbon monoxide levels of 25 to 77 people who escaped a burning
building. - accurate answers-The data set is a sample because the collection of
25 people is a subset of the 77 people who escaped a burning building.
sixty seven of the 92 passengers aboard an airship survived an explosion. -
accurate answers-the number is a population parameter because it is a
numerical description of all the passengers that survived
Name each level of measurement for which data can be quantative - accurate
answers-interval, ratio, ordinal
Distance in miles from one city to another - accurate answers-the variable is
quantitive because distance in miles is found by measuring or coutning
What is the difference between a random sample and a simple random sample
- accurate answers-With a random sample, each individual has the same
chance of being selected. With a simple random sample, all samples of the
same size have the same chance of being selected.
systematic sampling - accurate answers-Every nth item in the target
population is selected
Use the given minimum and maximum data entries, and the number of classes,
to find the class width, the lower class limits, and the upper class limits.
, minimum= 7, maximum=90, 6classes - accurate answers-The class width is 14
Lower class limits= 7,221,35,49,63,67
Upper class limits= 20,34,48,62,76,90
Why should the number of classes in a frequency distribution be between 5
and 20? - accurate answers-If the number of classes in a frequency
distribution is not between 5 and 20, it may be difficult to detect any patterns.
How to calculate relative frequency - accurate answers-frequency in
category/total frequency
How to calculate cumulative frequency - accurate answers-first frequency is
the same as frequency and you add the second, third, etc frequency
In terms of displaying data, how is a stem and leaf plot similar to a data plot? -
accurate answers-Both plots can be used to determine specific date entries.
Both plots can be used to identify unusual date values.
Both plots show how data is distributed
True or False: the mean is the measure of central tendency most likely to be
affected by an outlier - accurate answers-the statement is true
True or False: the date set can have the same mean, median and mode -
accurate answers-the statement is true
Why is the standard deviation used more frequently than the variance? -
accurate answers-The units of variance are squared. Its units are meaningless.
Explain the relationship between variance and standard deviation. Can either
of these measures be negative? Explain. - accurate answers-The standard
deviation is the positive square root of the variance. The standard deviation
and variance can never be negative. Squared deviations can never be negative.
how to find population variance - accurate answers-Step 1: Draw a table.
Label the columns as shown and then write down your X values (the items in
your population) in column 1
How is a sample related to a population? - accurate answers-A sample is a
subset of a population.
Why is a sample used more often than a population? - accurate answers-It is
usually impossible to count the entire population
What is the difference between a parameter and a statistic? - accurate
answers-A parameter is a numerical description of a population characteristic.
A statistic is a numerical description of a sample characteristic.
What are the two main divisions of statistics? - accurate answers-descriptive
and inferential
Determine whether the data set is a population of a sample.
The carbon monoxide levels of 25 to 77 people who escaped a burning
building. - accurate answers-The data set is a sample because the collection of
25 people is a subset of the 77 people who escaped a burning building.
sixty seven of the 92 passengers aboard an airship survived an explosion. -
accurate answers-the number is a population parameter because it is a
numerical description of all the passengers that survived
Name each level of measurement for which data can be quantative - accurate
answers-interval, ratio, ordinal
Distance in miles from one city to another - accurate answers-the variable is
quantitive because distance in miles is found by measuring or coutning
What is the difference between a random sample and a simple random sample
- accurate answers-With a random sample, each individual has the same
chance of being selected. With a simple random sample, all samples of the
same size have the same chance of being selected.
systematic sampling - accurate answers-Every nth item in the target
population is selected
Use the given minimum and maximum data entries, and the number of classes,
to find the class width, the lower class limits, and the upper class limits.
, minimum= 7, maximum=90, 6classes - accurate answers-The class width is 14
Lower class limits= 7,221,35,49,63,67
Upper class limits= 20,34,48,62,76,90
Why should the number of classes in a frequency distribution be between 5
and 20? - accurate answers-If the number of classes in a frequency
distribution is not between 5 and 20, it may be difficult to detect any patterns.
How to calculate relative frequency - accurate answers-frequency in
category/total frequency
How to calculate cumulative frequency - accurate answers-first frequency is
the same as frequency and you add the second, third, etc frequency
In terms of displaying data, how is a stem and leaf plot similar to a data plot? -
accurate answers-Both plots can be used to determine specific date entries.
Both plots can be used to identify unusual date values.
Both plots show how data is distributed
True or False: the mean is the measure of central tendency most likely to be
affected by an outlier - accurate answers-the statement is true
True or False: the date set can have the same mean, median and mode -
accurate answers-the statement is true
Why is the standard deviation used more frequently than the variance? -
accurate answers-The units of variance are squared. Its units are meaningless.
Explain the relationship between variance and standard deviation. Can either
of these measures be negative? Explain. - accurate answers-The standard
deviation is the positive square root of the variance. The standard deviation
and variance can never be negative. Squared deviations can never be negative.
how to find population variance - accurate answers-Step 1: Draw a table.
Label the columns as shown and then write down your X values (the items in
your population) in column 1
