jawz

Which of the following statements about histograms and frequency polygons is least accurate?

A) A frequency polygon is constructed by plotting the midpoint of each interval on the horizontal axis.

B) A histogram connects points with a straight line.

C) A histogram and a frequency polygon both plot the absolute frequency on the vertical axis.

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In constructing a frequency polygon, the midpoint of each interval is plotted on the horizontal axis and the frequency of each interval is plotted on the vertical axis. Points are then connected with straight lines. A histogram is a bar chart of data that has been grouped into a frequency distribution – because it is a bar chart, there are no individual points to connect.

jawz

Which of the following indicates the frequency of an interval in a frequency distribution histogram?

A) Height of the corresponding bar.

B) Horizontal logarithmic scale.

C) Width of the corresponding bar.

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In a histogram, intervals are placed on horizontal axis, and frequencies are placed on the vertical axis. The frequency of the particular interval is given by the value on the vertical axis, or the height of the corresponding bar.

jawz

In a frequency distribution histogram, the frequency of an interval is given by the:

A) height multiplied by the width of the corresponding bar.

B) width of the corresponding bar.

C) height of the corresponding bar.

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In a histogram, intervals are placed on the horizontal axis, and frequencies are placed on the vertical axis. The frequency of a particular interval is given by the value on the vertical axis, or the height of the corresponding bar.

jawz

How is the relative frequency of an interval computed?

A) Dividing the frequency of that interval by the sum of all frequencies.

B) Dividing the sum of the two interval limits by 2.

C) Subtracting the lower limit of the interval by the upper limit.

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The relative frequency is the percentage of total observations falling within each interval. It is found by taking the frequency of the interval and dividing that number by the sum of all frequencies.

jawz

Which of the following best describes a frequency distribution? A frequency distribution is a grouping of:

A) selected data into intervals (classes) so that the number of observations in each of the non-overlapping intervals (classes) can be seen and tallied.

B) data into intervals (classes) so that the number of observations in each of the non-overlapping intervals (classes) can be seen and tallied.

C) independent intervals (classes) so that they can be seen and tallied.

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A frequency distribution is a tabular presentation of statistical data that aids the analysis of large data sets.

jawz

Which of the following statements regarding frequency distributions is least accurate? Frequency distributions:

A) summarize data into a relatively small number of intervals.

B) organize data into overlapping groups.

C) work with all types of measurement scales.

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Data in a frequency distribution must belong to only one group or interval. Intervals are mutually exclusive and non-overlapping.

jawz

A summary measure of a characteristic of an entire population is called a:

A) statistic.

B) parameter.

C) census.

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A parameter measures a characteristic of the underlying population.

jawz

Which of the following is an example of a parameter?

A) Population variance.

B) Sample standard deviation.

C) Sample mean.

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A parameter is any descriptive measure of a population characteristic. The population variance describes a population while the sample standard deviation and sample mean are each descriptive measures of samples.

jawz

Which of the following statements regarding various statistical measures is least accurate?

A) The correlation coefficient is calculated by dividing the covariance of two random variables by the product of their standard deviations.

B) Variance equals the sum of the squared deviations from the mean times the probability that that each outcome will occur.

C) The coefficient of variation is calculated by dividing the mean by the standard deviation.

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The coefficient of variation equals the standard deviation divided by the mean.

jawz

What is the main difference between descriptive statistics and inferential statistics? Descriptive statistics are:

A) used to summarize data while inferential statistics are used to obtain precise information about a large data set.

B) used to make forecasts about the likelihood of upcoming events while inferential statistics are used to summarize any data set.

C) used to summarize a large data set while inferential statistics involves procedures used to make forecasts or judgments about a large data set by examining a smaller sample.

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Descriptive statistics are used to summarize a large data set while inferential statistics are based on procedures used to make forecasts or judgments about a large data set by examining a smaller set of data.