Chapter 2

Question 1

Cumulative relative frequency graph

Answer 1

Used to examine location within a distribution.
Cumulative relative frequency graphs begin by grouping the observations into equalwidth
classes

Question 2

Density curve

Answer 2

A curve that (a) is always on or above the horizontal axis, and (b) has
exactly 1 area underneath it. A density curve describes the overall pattern of a
distribution

Question 3

Mean of a density curve

Answer 3

The point at which the curve would balance if made of solid

material

Question 4

Median of a density curve

Answer 4

The point with half the area under the curve to its left and

the remaining half of the area to its right

Question 5

Normal curves

Answer 5

An important class of density curves that are symmetric, single-peaked,
and bell-shaped.

Question 6

Normal distribution

Answer 6

Described by a Normal density curve. Any particular Normal
distribution is completely specified by two numbers, its mean μ and standard deviation σ.
The mean of a Normal distribution is at the center of the symmetric Normal curve. The
standard deviation is the distance from the center to the change-of-curvature points on
either side

Question 7

Pth percentile

Answer 7

The value with p percent of the observations less than it

Question 8

Standard Normal distribution

Answer 8

The Normal distribution with mean 0 and standard

deviation 1

Question 9

Standard Normal table (Table A)

Answer 9

A table of areas under the standard Normal curve.

The table entry for each value z is the area under the curve to the left of z

Question 10

Standardized values (z-scores) I

Answer 10

If x is an observation from a distribution that has known
mean and standard deviation, the standardized value of x is mean
standard deviation
x
z − = . A
standardized value is often called a z-score.