Stats HW1,2,3.5,6,7 and 10 | Questions and Answers
In the distribution of a set of grouped data, the proportion of the total frequency that is in any
given class interval is given by the __________.
a. class midpoint
b. relative frequency
c. median class frequency
d. cumulative frequency
e. modal class frequency ** Answ** b. relative frequency
The sum of the relative frequencies of a grouped data set is always equal to one.
a. True
b. False ** Answ** a. True
A two-dimensional plot of pairs of points from two numerical variables is called a scatter plot.
Select one:
True
False ** Answ** True
In a stem and leaf plot of numbers with five digits, the stem has two digits. For the number,
48209, the leaf is __________.
Select one:
a. 209
b. 482
c. 096
d. 426
e. 420 ** Answ** a. 209
The representative value for each class in most group statistics calculations is the class interval.
Select one:
,True
False ** Answ** False
A vertical bar chart that displays the frequency of observations ranked in order of occurrence
from left to right is called a relative frequency histogram.
Select one:
True
False ** Answ** False
A cumulative frequency distribution is also called an ogive.
Select one:
True
False ** Answ** True
A graphical mechanism for examining the relationship between two numerical variables is called
a __________.
Select one:
a. dot plot
b. cause-and-effect diagram
c. scatter plot
d. pie chart
e. stem and leaf plot ** Answ** c. scatter plot
The range of a data set is defined as the difference between the mean and the median.
Select one:
True
False ** Answ** False
The difference between the smallest and largest numbers of a data set is the __________.
Select one:
a. deviation
, b. class frequency
c. range
d. average
e. variation ** Answ** c. range
HW 2
In recent years, due to low interest rates, many homeowners refinanced their home mortgages.
Below is the amount refinanced for 20 loans processed last week. The data are reported in
thousands of pounds and arranged from smallest to largest.
59.2 59.5 61.6 65.5 66.6 72.9 74.8 77.3 79.2
83.7 85.6 85.8 86.6 87.0 87.1 90.2 93.3 98.6
100.2 100.7
Question: What is the 26th percentile? (use two decimal places) ** Answ** 72.90
The mean of a distribution is 43, the median is 45, and the mode is 48. It is most likely that this
distribution is ___________ .
Select one:
a. symmetrical
b. asymptotic
c. leptokurtic
d. positively skewed
e. negatively skewed ** Answ** e. negatively skewed
Suppose that IQ scores have a bell-shaped distribution with a mean of 100 and a standard
deviation of 15.
Question: What percentage of people have an IQ score between 85 and 115?
(Please answer in the format xx e.g. '55' for 55%). ** Answ** 68
In the distribution of a set of grouped data, the proportion of the total frequency that is in any
given class interval is given by the __________.
a. class midpoint
b. relative frequency
c. median class frequency
d. cumulative frequency
e. modal class frequency ** Answ** b. relative frequency
The sum of the relative frequencies of a grouped data set is always equal to one.
a. True
b. False ** Answ** a. True
A two-dimensional plot of pairs of points from two numerical variables is called a scatter plot.
Select one:
True
False ** Answ** True
In a stem and leaf plot of numbers with five digits, the stem has two digits. For the number,
48209, the leaf is __________.
Select one:
a. 209
b. 482
c. 096
d. 426
e. 420 ** Answ** a. 209
The representative value for each class in most group statistics calculations is the class interval.
Select one:
,True
False ** Answ** False
A vertical bar chart that displays the frequency of observations ranked in order of occurrence
from left to right is called a relative frequency histogram.
Select one:
True
False ** Answ** False
A cumulative frequency distribution is also called an ogive.
Select one:
True
False ** Answ** True
A graphical mechanism for examining the relationship between two numerical variables is called
a __________.
Select one:
a. dot plot
b. cause-and-effect diagram
c. scatter plot
d. pie chart
e. stem and leaf plot ** Answ** c. scatter plot
The range of a data set is defined as the difference between the mean and the median.
Select one:
True
False ** Answ** False
The difference between the smallest and largest numbers of a data set is the __________.
Select one:
a. deviation
, b. class frequency
c. range
d. average
e. variation ** Answ** c. range
HW 2
In recent years, due to low interest rates, many homeowners refinanced their home mortgages.
Below is the amount refinanced for 20 loans processed last week. The data are reported in
thousands of pounds and arranged from smallest to largest.
59.2 59.5 61.6 65.5 66.6 72.9 74.8 77.3 79.2
83.7 85.6 85.8 86.6 87.0 87.1 90.2 93.3 98.6
100.2 100.7
Question: What is the 26th percentile? (use two decimal places) ** Answ** 72.90
The mean of a distribution is 43, the median is 45, and the mode is 48. It is most likely that this
distribution is ___________ .
Select one:
a. symmetrical
b. asymptotic
c. leptokurtic
d. positively skewed
e. negatively skewed ** Answ** e. negatively skewed
Suppose that IQ scores have a bell-shaped distribution with a mean of 100 and a standard
deviation of 15.
Question: What percentage of people have an IQ score between 85 and 115?
(Please answer in the format xx e.g. '55' for 55%). ** Answ** 68
