STT 231 WEEK 1 (LECTURE 1, 2, 3) EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE
2026
population - Answers totality of the individuals or objects that are of interest in a statistical
study/total group of individuals or objects that you want to make conclusions about
sample - Answers small part or a subset of a population/should be representative of the
population/used to make conclusions about the population
descriptive statistics - Answers describing a data set in a simple, understandable fashion
statistic - Answers number computed from data
randomization - Answers chooses at random to eliminate bias
placebo control study - Answers subjects receive what they think is the treatment but is actually not
making those subjects a control group (the individual giving the treatment is aware of which
treatment the subject is receiving)
double blind study - Answers the treatment group and control group is decided by an outside third
party and neither the subjects or the individuals running the study are aware of which group is which
parameter - Answers numerical study of the POPULATION
statistic - Answers numerical summary of SAMPLE from population
data - Answers systematically recored information
The 5 W's of data - Answers who, what, where, when, why, how
raw data - Answers numbers and category labels that have been collected but have not yet been
processed in any way
row - Answers horizontal, represents cases or individual
column - Answers vertical, represents variables
variables - Answers characteristics recorded about each case or individual or subject
categorical/qualitative - Answers groups and categories
ordinal variables - Answers categorical variables with categories in logical order
quantitative/numerical - Answers numerical values taken from each individual (measure, counted)
discrete variable - Answers quantitative variable with values from a countable set of numbers or from
a finite set of numbers, separate values
continuous variable - Answers quantitative variable that takes its possible values in an interval or a
range (continuum) or the entire real number line (IR) measured
IR (double lined R) - Answers Real number line: no holes, all rational, irrational, negative positive
numbers
In June 2000, a homeowner in Tuscola, Illinois, wanted to determine if generic fertilizers and weed
killers are as effective as the more expensive branded products. After the spring rains and early
summer warmth, she counted the number of weeds and measured density of grass blades.
Identify who, where, when, and why for the situation described:
A. Homeowner; Tuscola, Illinois; June 2000; Compare products.
B. Lawn; Tuscola, Illinois; June 2001; Compare products.
C. Lawn; Arcola, Illinois; June 2000; compare products.
D. Homeowner; Arcola, Illinois; June 2000; Compare products.
E. Lawn; Tuscola, Illinois; June 2000; Compare products.
16 - Answers E
In June 2003 CONSUMER REPORTS published an article on some sports utility vehicles that they had
tested recently. They reported some basic information about each of the vehicles and the results of
some tests conducted by their staff.
Among other things, the article mentioned the brand of each vehicle, the price, and whether the
vehicle had a standard or automatic transmission.
They reported the vehicle's fuel economy, acceleration, number of seconds to go from zero to 60mph
and braking distance to stop when travelling at 60mph.
The article also rated each vehicle's reliability: namely, better than average, average, worse, or much
worse than average.
Identify the W's.
List the variables. Indicate whether each variable is categorical or quantitative.
If the variable is quantitative, indicate the units. - Answers The Ws: who: sports utility vehicles
what: the characteristics
when: 2003
2026
population - Answers totality of the individuals or objects that are of interest in a statistical
study/total group of individuals or objects that you want to make conclusions about
sample - Answers small part or a subset of a population/should be representative of the
population/used to make conclusions about the population
descriptive statistics - Answers describing a data set in a simple, understandable fashion
statistic - Answers number computed from data
randomization - Answers chooses at random to eliminate bias
placebo control study - Answers subjects receive what they think is the treatment but is actually not
making those subjects a control group (the individual giving the treatment is aware of which
treatment the subject is receiving)
double blind study - Answers the treatment group and control group is decided by an outside third
party and neither the subjects or the individuals running the study are aware of which group is which
parameter - Answers numerical study of the POPULATION
statistic - Answers numerical summary of SAMPLE from population
data - Answers systematically recored information
The 5 W's of data - Answers who, what, where, when, why, how
raw data - Answers numbers and category labels that have been collected but have not yet been
processed in any way
row - Answers horizontal, represents cases or individual
column - Answers vertical, represents variables
variables - Answers characteristics recorded about each case or individual or subject
categorical/qualitative - Answers groups and categories
ordinal variables - Answers categorical variables with categories in logical order
quantitative/numerical - Answers numerical values taken from each individual (measure, counted)
discrete variable - Answers quantitative variable with values from a countable set of numbers or from
a finite set of numbers, separate values
continuous variable - Answers quantitative variable that takes its possible values in an interval or a
range (continuum) or the entire real number line (IR) measured
IR (double lined R) - Answers Real number line: no holes, all rational, irrational, negative positive
numbers
In June 2000, a homeowner in Tuscola, Illinois, wanted to determine if generic fertilizers and weed
killers are as effective as the more expensive branded products. After the spring rains and early
summer warmth, she counted the number of weeds and measured density of grass blades.
Identify who, where, when, and why for the situation described:
A. Homeowner; Tuscola, Illinois; June 2000; Compare products.
B. Lawn; Tuscola, Illinois; June 2001; Compare products.
C. Lawn; Arcola, Illinois; June 2000; compare products.
D. Homeowner; Arcola, Illinois; June 2000; Compare products.
E. Lawn; Tuscola, Illinois; June 2000; Compare products.
16 - Answers E
In June 2003 CONSUMER REPORTS published an article on some sports utility vehicles that they had
tested recently. They reported some basic information about each of the vehicles and the results of
some tests conducted by their staff.
Among other things, the article mentioned the brand of each vehicle, the price, and whether the
vehicle had a standard or automatic transmission.
They reported the vehicle's fuel economy, acceleration, number of seconds to go from zero to 60mph
and braking distance to stop when travelling at 60mph.
The article also rated each vehicle's reliability: namely, better than average, average, worse, or much
worse than average.
Identify the W's.
List the variables. Indicate whether each variable is categorical or quantitative.
If the variable is quantitative, indicate the units. - Answers The Ws: who: sports utility vehicles
what: the characteristics
when: 2003
