CNSL 503 Statistics Final Exam with 150
Practice Questions and Correct Answers/
CNSL 503 Final Practice Test
when the frequency for every value in a dataset is presented, a __________ is
formed:
- frequency diffusion
- frequency distribution
- frequency dispersion
- frequency dispersal
frequency distribution
a range of scores can be grouped in sets called ____________.
bins
groups
categories
chunks
Answer: BINS Explanation: when there is a wide range of values a grouped
frequency distribution table can be used. Bins are used!
calculate the range for the following scores: 45, 64, 32, 58, 43
Range = Xmax - Xmin
range = 64 -32
=32
Which of the following is a measure of variability?
- mean
- median
- range
- mode
range
what is central tendency?
1
,one way to describe data; it is an average or middle value that describes the center
of a distribution. Mean, median, and mode are three measures of central tendency
True or false: outliers are always the result of errors in data collection
FALSE! outliers may be legitimate values that should be included in the results
True or false: frequency tables are used to display both qualitative and quantitative
data.
TRUE! displays the number of times a certain value appears within the dataset
(frequency). One of the easiest ways to summarize a set of score or values.
identify the mode in the following set of scores: 438, 421, 423, 432, 440, 435, 441
there is no mode because every value appears the same number of times (once)
Why are pie charts not used frequently by researchers and statisticians?
The effectiveness of pie charts is limited to datasets with only a few categories
My answer: they are best with a small number of relative frequencies - too many
"slices" make it difficult to interpret the pie chart
the sum of all relative frequencies in a dataset will always equal ____________.
1 or 100%
Calculate the mean for the following set of scores: 89, 75, 91, 68, 72, 83, 94, 78
mean (x̄) = ∑ (sum of) X / n
x̄ = (89 + 75 + 91 + 68 + 72 + 83 + 94 + 78) / 8
= 81.25
true or false: the median is affected by outliers
FALSE! Neither the mode nor median is affected by outliers. It IS possible for the
mean to be affected.
a neuropsychologist records the scores on the MMSE (Mini-Mental State
Examination) for 30 patients. Every score appears once in the dataset. What would
this distribution be known as?
- multimodal distribution
- uniform distribution
2
,- bimodal distribution
- unimodal distribution
Answer: Uniform distribution. Explanation: distribution can be described by shape
and symmetry. The number of peaks is determined by # number of modes. Since
there is no mode it is uniform distribution.
determine the median for the following set of scores: 2121, 2115, 2117, 2120,
2118, 2122
First put in order from least to greatest (2115, 2117, 2118, 2120, 2121, 2122). Then
find the middle number. If there is two take the mean of the two.
(2118 + 2120) / 2 = 2119
the bars of __________ do not touch because they represent discrete values,
whereas the bars of ________ do touch because they represent continuous values
Answer: bar graph; histogram Explanation: each bar in a bar graph/bar chart
represents an individual category.
Aaron scores a mean of 85 (s = 8) on 4 of his cognitive psychology exams for fall
semester. Kyle scores a mean of 83 (s = 4) on the cognitive psychology exams.
Does Aaron or Kyle have the more consistent performance on the exams?
Kyle because his standard deviation (s) was lower, which indicates less variability
in his test scores compared to aaron
Which type of graph clearly depicts the shape of a distribution?
FREQUENCY POLYGON because the increasing and decreasing sections of the
data can be seen
In a symmetrical distribution, what is the most commonly used measure of central
tendency?
Answer: MEAN Note: in a symmetrical distribution, the mean/median/mode are all
the same value
researchers are studying the average miles per gallon (mpg) of different cars based
on size (compact, mid-size, and full-size) and make (Ford, Chevy, and Chrysler).
Would a three dimensional graph be appropriate to use to display these data?
Explain.
3
, Yes because there are three variables being measured (mpg, car size, and car
make). So a three dimensional graph would be the best choice.
three dimensional graph is best for "three dimensional data"
seven food trucks are competing to see how many customers visit their trucks per
day in a busy part of the city. The average number of customers that visit each food
truck per day is 281. The sum of squares is found to be 187. calculate the variance
for these data
s² or σ² (variance) = ∑ (X - x̄)^2 / (n - 1) and ∑ (X - x̄)^2 = SS (sum of squares)
variance = sum of (term in data set - sample mean) squared / (sample size - 1)
sum of squares = 187
s² = 187 / (7-1)
= 31.17
a gardener has 5 apple trees in her yard. Each tree has a different number of apples
growing on it. The following list represents the number of apples on each tree: 22,
29, 31, 23, 27. Calculate the standard deviation of these values (x̄ = 26.4)
Standard deviation (s) = √ (variance)
√ ∑ (X - x̄)^2 / (n - 1) and ∑ (X - x̄)^2 = SS. So, ∑ (19.36 + 6.76 + 21.16 + 11.56 +
0.36) = 59.2
√ (59.-1) = √ 14.8
= 3.85
a professor posts the final exam grades for 50 of his psychology students. Most of
the scores are clustered on the lower side of the distribution, with a few scores
falling toward the right. What term would be best describe the distribution? what
does this imply about how hard the test was?
this would be considered a positively skewed (right-skewed) distribution, as most
of the scores fall on the left side of the distribution and the skew or "tail" is over
the right side. This would indicate that the test was very difficult, as most students
scored low on the exam
true or false: a statistic applies to a population, and a parameter applies to a sample
FALSE! A statistic applies to a sample, whereas a parameter applies to a
population
4
Practice Questions and Correct Answers/
CNSL 503 Final Practice Test
when the frequency for every value in a dataset is presented, a __________ is
formed:
- frequency diffusion
- frequency distribution
- frequency dispersion
- frequency dispersal
frequency distribution
a range of scores can be grouped in sets called ____________.
bins
groups
categories
chunks
Answer: BINS Explanation: when there is a wide range of values a grouped
frequency distribution table can be used. Bins are used!
calculate the range for the following scores: 45, 64, 32, 58, 43
Range = Xmax - Xmin
range = 64 -32
=32
Which of the following is a measure of variability?
- mean
- median
- range
- mode
range
what is central tendency?
1
,one way to describe data; it is an average or middle value that describes the center
of a distribution. Mean, median, and mode are three measures of central tendency
True or false: outliers are always the result of errors in data collection
FALSE! outliers may be legitimate values that should be included in the results
True or false: frequency tables are used to display both qualitative and quantitative
data.
TRUE! displays the number of times a certain value appears within the dataset
(frequency). One of the easiest ways to summarize a set of score or values.
identify the mode in the following set of scores: 438, 421, 423, 432, 440, 435, 441
there is no mode because every value appears the same number of times (once)
Why are pie charts not used frequently by researchers and statisticians?
The effectiveness of pie charts is limited to datasets with only a few categories
My answer: they are best with a small number of relative frequencies - too many
"slices" make it difficult to interpret the pie chart
the sum of all relative frequencies in a dataset will always equal ____________.
1 or 100%
Calculate the mean for the following set of scores: 89, 75, 91, 68, 72, 83, 94, 78
mean (x̄) = ∑ (sum of) X / n
x̄ = (89 + 75 + 91 + 68 + 72 + 83 + 94 + 78) / 8
= 81.25
true or false: the median is affected by outliers
FALSE! Neither the mode nor median is affected by outliers. It IS possible for the
mean to be affected.
a neuropsychologist records the scores on the MMSE (Mini-Mental State
Examination) for 30 patients. Every score appears once in the dataset. What would
this distribution be known as?
- multimodal distribution
- uniform distribution
2
,- bimodal distribution
- unimodal distribution
Answer: Uniform distribution. Explanation: distribution can be described by shape
and symmetry. The number of peaks is determined by # number of modes. Since
there is no mode it is uniform distribution.
determine the median for the following set of scores: 2121, 2115, 2117, 2120,
2118, 2122
First put in order from least to greatest (2115, 2117, 2118, 2120, 2121, 2122). Then
find the middle number. If there is two take the mean of the two.
(2118 + 2120) / 2 = 2119
the bars of __________ do not touch because they represent discrete values,
whereas the bars of ________ do touch because they represent continuous values
Answer: bar graph; histogram Explanation: each bar in a bar graph/bar chart
represents an individual category.
Aaron scores a mean of 85 (s = 8) on 4 of his cognitive psychology exams for fall
semester. Kyle scores a mean of 83 (s = 4) on the cognitive psychology exams.
Does Aaron or Kyle have the more consistent performance on the exams?
Kyle because his standard deviation (s) was lower, which indicates less variability
in his test scores compared to aaron
Which type of graph clearly depicts the shape of a distribution?
FREQUENCY POLYGON because the increasing and decreasing sections of the
data can be seen
In a symmetrical distribution, what is the most commonly used measure of central
tendency?
Answer: MEAN Note: in a symmetrical distribution, the mean/median/mode are all
the same value
researchers are studying the average miles per gallon (mpg) of different cars based
on size (compact, mid-size, and full-size) and make (Ford, Chevy, and Chrysler).
Would a three dimensional graph be appropriate to use to display these data?
Explain.
3
, Yes because there are three variables being measured (mpg, car size, and car
make). So a three dimensional graph would be the best choice.
three dimensional graph is best for "three dimensional data"
seven food trucks are competing to see how many customers visit their trucks per
day in a busy part of the city. The average number of customers that visit each food
truck per day is 281. The sum of squares is found to be 187. calculate the variance
for these data
s² or σ² (variance) = ∑ (X - x̄)^2 / (n - 1) and ∑ (X - x̄)^2 = SS (sum of squares)
variance = sum of (term in data set - sample mean) squared / (sample size - 1)
sum of squares = 187
s² = 187 / (7-1)
= 31.17
a gardener has 5 apple trees in her yard. Each tree has a different number of apples
growing on it. The following list represents the number of apples on each tree: 22,
29, 31, 23, 27. Calculate the standard deviation of these values (x̄ = 26.4)
Standard deviation (s) = √ (variance)
√ ∑ (X - x̄)^2 / (n - 1) and ∑ (X - x̄)^2 = SS. So, ∑ (19.36 + 6.76 + 21.16 + 11.56 +
0.36) = 59.2
√ (59.-1) = √ 14.8
= 3.85
a professor posts the final exam grades for 50 of his psychology students. Most of
the scores are clustered on the lower side of the distribution, with a few scores
falling toward the right. What term would be best describe the distribution? what
does this imply about how hard the test was?
this would be considered a positively skewed (right-skewed) distribution, as most
of the scores fall on the left side of the distribution and the skew or "tail" is over
the right side. This would indicate that the test was very difficult, as most students
scored low on the exam
true or false: a statistic applies to a population, and a parameter applies to a sample
FALSE! A statistic applies to a sample, whereas a parameter applies to a
population
4
