Statistics Midterm
Question 1
A scatterplot shows a negative association between two variables. What is the best
description of this graph?
● The points plotted indicate a bad relationship between the variables.
● The points plotted indicate no trend.
● The points plotted indicate an upward trend.
● The points plotted indicate a downward trend.
Question 2
A study is commissioned to measure the effects of a new drug on a patient's number of
heartbeats per minute. The study is hoping to find the ideal dosage to give a patient who is
hospitalized for a rapid heartbeat. A sample of 75 people who deal with chronic rapid
heartbeat is selected for the study.
What is the response variable in the study?
● The patient's number of heartbeats per minute
● The dosage of the new drug
● The number of people hospitalized annually for rapid heartbeat
● The sample of 75 selected for the study
Question 3
Officer Freddy Heflin is using his radar equipment to monitor the speeds of motorists in
Garrison, New Jersey. The radar equipment only displays a motorist's speed to the nearest
whole number in miles per hour. Classify the variable that represents the speed of a motorist,
according to the radar equipment.
● Categorical
● Nominal
● Continuous numerical
● Discrete numerical
Question 4
A medical supply company wants to know how many of its Holter monitors are in complete
working order. The company randomly selects 325 Holter monitors in its factory and fully
inspects them. Describe the sample in this situation.
● All of the company’s Holter monitors at its warehouse
● All Holter monitors in the US
● The 325 randomly selected Holter monitors
, ● All working Holter monitors at its warehouse
Question 5
To check the accuracy of a machine filling coffee cups, a worker randomly selects 20 such
machines, and the number of ounces of coffee filled by the machine is measured. Which
sampling method was used in this situation?
● Cluster sampling
● Systematic sampling
● Simple random sampling
● Stratified sampling
Question 6
Researchers studied the habits of bank robbers in an effort to reduce the number of bank
robberies that take place. The researchers poured over years of data and camera footage
related to bank robberies, studied the bank robbers that were caught, and analyzed how much
money was stolen on average. What type of study is demonstrated here?
● Observational
● Experimental
Question 7
Which of the following statements are true about the mean, median and/or the mode of a data
set?
I. The median is always the average of the middle two values in the data set, once the data set
is ordered from least to greatest.
II. The mean is found by adding up all the values in the data set and dividing by the
number of values in the set.
III. The mean, median and mode are considered measures of central tendency for the
data set.
IV. The values in the data set must first be ordered from least to greatest to calculate the
mean.
V. The mean, median and mode are considered measures of spread for the data set.
Answer:
● II and III
Question 9
Calculate the mean for the data set below:
-6.33, -49.94, -22.29, -17.70, -64.3, -17.07, -60.90, 64.3, -49.94, 20.51
Question 1
A scatterplot shows a negative association between two variables. What is the best
description of this graph?
● The points plotted indicate a bad relationship between the variables.
● The points plotted indicate no trend.
● The points plotted indicate an upward trend.
● The points plotted indicate a downward trend.
Question 2
A study is commissioned to measure the effects of a new drug on a patient's number of
heartbeats per minute. The study is hoping to find the ideal dosage to give a patient who is
hospitalized for a rapid heartbeat. A sample of 75 people who deal with chronic rapid
heartbeat is selected for the study.
What is the response variable in the study?
● The patient's number of heartbeats per minute
● The dosage of the new drug
● The number of people hospitalized annually for rapid heartbeat
● The sample of 75 selected for the study
Question 3
Officer Freddy Heflin is using his radar equipment to monitor the speeds of motorists in
Garrison, New Jersey. The radar equipment only displays a motorist's speed to the nearest
whole number in miles per hour. Classify the variable that represents the speed of a motorist,
according to the radar equipment.
● Categorical
● Nominal
● Continuous numerical
● Discrete numerical
Question 4
A medical supply company wants to know how many of its Holter monitors are in complete
working order. The company randomly selects 325 Holter monitors in its factory and fully
inspects them. Describe the sample in this situation.
● All of the company’s Holter monitors at its warehouse
● All Holter monitors in the US
● The 325 randomly selected Holter monitors
, ● All working Holter monitors at its warehouse
Question 5
To check the accuracy of a machine filling coffee cups, a worker randomly selects 20 such
machines, and the number of ounces of coffee filled by the machine is measured. Which
sampling method was used in this situation?
● Cluster sampling
● Systematic sampling
● Simple random sampling
● Stratified sampling
Question 6
Researchers studied the habits of bank robbers in an effort to reduce the number of bank
robberies that take place. The researchers poured over years of data and camera footage
related to bank robberies, studied the bank robbers that were caught, and analyzed how much
money was stolen on average. What type of study is demonstrated here?
● Observational
● Experimental
Question 7
Which of the following statements are true about the mean, median and/or the mode of a data
set?
I. The median is always the average of the middle two values in the data set, once the data set
is ordered from least to greatest.
II. The mean is found by adding up all the values in the data set and dividing by the
number of values in the set.
III. The mean, median and mode are considered measures of central tendency for the
data set.
IV. The values in the data set must first be ordered from least to greatest to calculate the
mean.
V. The mean, median and mode are considered measures of spread for the data set.
Answer:
● II and III
Question 9
Calculate the mean for the data set below:
-6.33, -49.94, -22.29, -17.70, -64.3, -17.07, -60.90, 64.3, -49.94, 20.51
