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Flashcards in Chapter 2 Deck (24):
1

The ___ _____ of a distribution is the value with ā€˜pā€™ percent of the observations less than it

Pth percentile

2

Another name for a cumulative frequency graph is an ______

Ogive

3

__ is equal to the 25th percentile

Q1

4

The median is equal to the ____ percentile

50th

5

__ is equal to the 75th percentile

Q3

6

_____________ is the formula for a z-score

(X-mean)/standard deviation

7

In a histogram, our eyes respond to the areas of the bars. These bars represent _______ of the observations

Proportions

8

A density curve has a total area under the curve of ___. Ares under the curve represent _______ of the observations

Areas, proportions

9

______, are not described by the density curve. No real set of data is described.

Outliers

10

The ______ of the density curve is the equal areas point-the point with 1/2 of the data to the left and 1/2 of the data to the right.

Median

11

The _____ of the density curve is the point at which the curve would balance if are of solid material

Mean

12

The means and the median of a symmetric density curve are _____

Equal

13

The mean of a skewed curve is pulled away from the median in the direction of a ___ ____

Long tail

14

The density curve is an ____ set of data, so we must distinguish its mean and standard deviation from that of an actual set of data

Idealized

15

We use ___ and ___ for an actual set of data

X (bar over) and Sx

16

We use ___ for mean and ____ for standard deviation for an idealized set of data

Mu and sigma

17

____ _____ are density curves that are symmetric, single peaked, and bell shaped

Normal curve

18

The standard deviation controls the ____ of a normal curve

Spread

19

____ of the data falls between one standard deviation of the mean

68%

20

____ of the data falls between two standard deviations of the mean

95%

21

____ of the data falls between three standard deviations of the data

99.7%

22

The normal curve is described by _____

N(mu, sigma)

23

Adding and subtracting the same number to each observation adds it subtracts from the ___ __ _____, but not from _____ __ _______

Center or location, spread or shape

24

Multiplying and dividing each observation by the same number multiplied or divides the ___ __ _____, _____, and ______

Center or location, spread, shape