stats chapter 2
To construct a pie chart, first distribute the data as ______.
relative percentages
The range of scores in each interval of a grouped frequency distribution is called the ______.
interval width
Grouped data are distributed into ______, whereas ungrouped data are distributed into ______.
intervals; categories
To determine the interval width, we divide the ______ by the number of intervals.
real range
A percentile is ______.
a percentile point
A percentile point is ______.
. the value of a score on a measurement scale below which a specified percentage of scores in a distribution fall
The sum of relative frequencies for each interval is ______.
1.00
What is the percentile point at the 90th percentile in the following distribution?
10
A researcher finds that 12% of participants make between three and five visits to a physician each year. What are the real limits for this interval?
2.5-5.5
A researcher finds that 12 persons in a sample of 60 reported getting between 4 and 6 hr of sleep per night. What is the relative percentage for this interval?
20%
The following is a simple frequency distribution table. If we convert this frequency distribution to relative percentages, which of the following gives the corresponding relative percentages in each interval listed from the top down?
20%, 13%, 17%, 33%, 17%
What is the percentile point at the 50th percentile for the following distribution?
25
As a general rule, a simple frequency distribution should have between ______.
5 and 20 intervals
What is the percentile point at the 80th percentile in the following distribution?
8
Fill in the missing values for A and B in this frequency distribution table:
A = 3.2, B = 13
State the type of graphical display for Graph A and Graph B.
B is a bar chart; A is a histogram.
A researcher distributes frequencies into the following intervals: 1-10, 11-20, 21-30, 31-40, 41-50, and 51 and above. What is wrong with this frequency distribution?
One interval is an open class.
State the problem with this simple frequency distribution.
The class intervals overlap.
A researcher distributes frequencies into the following intervals: 3-6, 7-10, 11-15, 16-18, 19-22, and 23-26. What is wrong with this frequency distribution?
The interval width is unequal.
Which of the following is NOT a rule for constructing a simple frequency distribution?
The number of intervals should equal the number of values measured.
A student scores in the 80th percentile on an exam. What does this mean in comparison to all other students?
The student scored higher than 80% of all others who took the exam.
Which characteristic of a histogram implies that it summaries continuous data?
The vertical bars touch at the upper boundary of each interval.
A researcher wants to determine how many participants will take less than 24 s to complete a cognitive performance task. If he constructs a frequency distribution for these data, what type of distribution would be most appropriate to answer his question?
a cumulative frequency distribution from the bottom up
A researcher distributes frequencies into the following classes: absent, tardy, and present. What type of data is distributed?
all of these
A simple frequency distribution ______.
all of these
Grouped data can be distributed ______.
all of these
When cumulating frequencies from the bottom up, the data are discussed in terms of ______.
all of these
When cumulating frequencies from the top down, the data are discussed in terms of ______.
all of these
Which of the following is a type of graphical display used to summarize quantitative, continuous data?
all of these
A researcher records the number of children at a local school from single-, divorced-, and married-parent homes. These frequency data would be best displayed as a ______.
bar chart
Which of the following is a type of graphical display used to summarize qualitative, discrete data?
both A and B
The following is a simple frequency distribution table. Suppose we convert this table to a cumulative frequency distribution. The frequencies in each interval of the cumulative frequency distribution would be
both A and B, depending on how the data were summarized
Ungrouped data can be distributed as ______.
categories
Grouped data are to ungrouped data as ______.
continuous is to discrete
A psychologist wants to know how many of her clients continue with therapy for at least 12 days. If she constructs a frequency distribution for these data, what type of distribution would be most appropriate to answer her question?
cumulative frequency distribution from the top down
The three steps for constructing a simple frequency distribution are ______.
find the real range, find the interval width, and construct the frequency distribution
Which of the following requires the calculation of a real range?
frequency distributions for grouped data
A ______ is plotted at the midpoint of each interval, whereas a ______ is plotted at the upper boundary of each interval.
frequency polygon; ogive
A researcher summarizes a set of frequency data into five intervals. This is an example of a frequency distribution for ______.
grouped data
A graphical display for grouped frequency distributions with continuous data is called a ______.
histogram
A researcher measures the time (in seconds) that it takes children to complete a basic reading skills task. What type of graphical display would be most appropriate for summarizing the frequency of children falling into different intervals of time?
histogram
A researcher measures the weight (in ounces) of newborn infants in the month of March. What type of graphical display would be most appropriate for summarizing the frequency of infants falling into different intervals of weight?
histogram
Which graphical display lists percentages and not original scores?
ogive
A percentile is also called a ______.
percentile point
A cumulative percentage summary that indicates the percentage of scores at or below a given value is called a ______.
percentile rank
The ______ is the percentage of scores with values that fall below a specified score in a distribution.
percentile rank
Bar charts are a lot like histograms, except ______.
the bars displayed in the graph do not touch
What is the corresponding percentile of a percentile point?
the percentile rank
A relative frequency distribution is appropriate when ______.
there are large frequency counts in each interval
The following frequency distribution is an example of
ungrouped data