The study of statistics rests on? - Answers Variation and Data
The circles shown to the right are similar, but not exactly the same. This is an example of? - Answers
Variation
Data are more than just numbers, because data have _____. - Answers Context
Stacked Data
Converting Stacked to unstacked - Answers
In statistics, variables are_______. - Answers Characteristics of people and things.
In statistics, the data we work with is just one part of a bigger picture called the ____. - Answers
Population
Which of the following questions should be asked when developing an understanding of data? - Answers
What variables wereWh measured?
How were the variables measured?
Who collected the data?
(All of these questions are important.)
What are two basic types of variables in statistics? - Answers Numerical and categorical
The variable "eye color" is an example of what type of variable? - Answers Categorical
Categorical variables are also referred to as ______ variables. - Answers qualitative
The process of representing categorical variables with numbers (such as letting a 1 represent "smoker"
and a 0 represent "non-smoker") is called _______. - Answers Coding
It was predicted that a country will have an elderly population (65 and older) of 8,448,000 in the year
2050 and that this will be 19.3% of the population. What is the total predicted population of this country
in 2050? - Answers The total predicted population of the country in 2050 is 43,772,000
people.
, 8448000/0.193=43772020.725389
It was predicted that a country will have an elderly population (65 and older) of 8,170,000 in the year
2050 and that this will be 22.5% of the population. What is the total predicted population of this country
in 2050? - Answers The total predicted population of the country in 2050 is 36311000 people.
It was reported in 2007 that there were 8,987,000 people age 16 or older who had a "go outside the
home" disability and that this was 23.1% of the population (of this age group). These are people who
cannot go outside the home without help. How large was the total population (of this age group) in
2007? - Answers The population in 2007 of people (of this age group) 38905000 is people.
8987000/0.231=38904761.904762
Two sections of statistics are offered, the first at 8 a.m. and the second at 10 a.m. The 8 a.m. section has
25 women, and the 10 a.m. section has 15 women. A student claims this is evidence that women prefer
earlier statistics classes than men do. What information is missing that might contradict this claim? -
Answers The percentage of female students in the two classes is unknown. There may be more females
in the 8 a.m. because there are more students in the 8 a.m. class than the 10 a.m. class. This claim could
be true only if the classes were the same size.
In 2008, a highway safety administration reported that the number of pedestrian fatalities in City A was
65 and that the number in City B was 45. Can we conclude that pedestrians are safer in City B? Why or
why not? - Answers No, in order to compare the fatalities the statistics must include the number of
fatalities per pedestrian. There may be fewer pedestrians in City B causing the difference.
Which of the following is used to summarize two potentially related categorical variables? - Answers A
two-way table
The number of times a value is observed in a data set is called a ______. - Answers frequency
Why is it not possible to conclude which sport is the most dangerous by looking at the number of
injuries in the accompanying data table? - Answers The sports have different numbers of participants.
Why are percentages or rates often better than counts for making comparisons? - Answers They take
into account possible differences among the sizes of the groups.
A student watched picnickers with a large cooler of soft drinks to see whether teenagers were less likely
than adults to choose diet soft drinks over regular soft drinks. - Answers The study is
an observational study.
Indicate whether the following study is an observational study or a controlled experiment.