Chapter 1 & 2

Question 1

population

Answer 1

entire collection of individuals about which information is sought.

Question 2

parameter

Answer 2

a number that describes a population.

Question 3

sample

Answer 3

a subset of a population that are actually observed.

Question 4

statistic

Answer 4

Is a number that describes a sample.

Question 5

random sample

Answer 5

unbiased representation of a group

Question 6

sample of convenience

Answer 6

is made up of people who are easy to reach.

Question 7

voluntary

response samples

Answer 7

is a sample made up of volunteers, these types of samples are always biased.

Question 8

ordinal variables

Answer 8

qualitative - categories

have a natural order

Question 9

nominal variables

Answer 9

qualitative - categories

no natural order

Question 10

qualitative variables

Answer 10

Classified by categories.

Question 11

quantitative variables

Answer 11

Classified numerically

Question 12

discrete variables

Answer 12

quantitative - numerical value

value listed like whole numbers

Question 13

continuous variables

Answer 13

quantitative - numerical value

value decimal or fraction

Question 14

double-blind

Answer 14

neither of the investigators nor the subjects know who has been assigned to which treatment.

Question 15

confounding

Answer 15

Is a variable that influences both the dependent variable and independent variable causing a spurious association.

Question 16

longitudinal (prospective)

Answer 16

The subjects are followed over time.

Question 17

cross section

Answer 17

Measurements that are taken at one point in time.

Question 18

retrospective

Answer 18

A cohort study where subjects are sampled after the outcome has occurred.

Question 19

bias

Answer 19

Is the degree to which a procedure systematically overestimates or underestimates a population value.

Question 20

dot plot

Answer 20

is a statistical chart consisting of data points plotted on a fairly simple scale, typically using filled in circles.

Question 21

pie chart

Answer 21

a type of graph in which a circle is divided into sectors that each represent a proportion of the whole.

Question 22

frequency histogram

Answer 22

is a type of bar graph that shows the frequency, or number of times, an outcome occurs in a data set. It has a title, an x-axis, a y-axis, and vertical bars to visually represent the data.

Question 23

relative frequency histogram

Answer 23

A relative frequency histogram uses the same information as a frequency histogram but compares each class interval to the total number of items.

Question 24

How can graphs be

misleading?

Answer 24

The “classic” types of misleading graphs include cases where: The Vertical scale is too big or too small, or skips numbers, or doesn’t start at zero. The graph isn’t labeled properly. Data is left out.

Question 25

frequency ogive

Answer 25

plots cumulative frequencies

Question 26

classes

Answer 26

are intervals of equal width that cover all the values that are observed.

Question 27

skewed

Answer 27

A histogram is skewed if one side, or tail is longer than the other.

Question 28

unimodal

Answer 28

A histogram is unimodal if it only has one mode.

Question 29

bimodal

Answer 29

A histogram is bimodal if it has two clearly distinct modes.

Question 30

frequency polygons

Answer 30

are plotted by making a point for each class. the x-coordinate of the point is the class midpoint and y-coordinate is the frequency of the class. we then connect all points with a straight line.

Question 31

mode

Answer 31

a peak or a high point of a histogram.