chapter 2

Question 1

class width

Answer 1

(max # - max #) / # of classes

Question 2

midpoint

Answer 2

(lower class + higher class) / 2

Question 3

Relative frequency

Answer 3

class frequency / sample size

Question 4

Σx

Answer 4

adding all the data enteries together

Question 5

Σ

Answer 5

sigma

Question 6

cumulative frequency

Answer 6

sum of that class and all previous classes

Question 7

histogram

Answer 7

bars touch ( -0.5 from lower class and +0.5 from upper class)

Question 8

frequency polygon

Answer 8

line graph that touches x-axis on both sides

Question 9

Ogive

Answer 9

touches the x-axis on its first point; line graph

Question 10

Stemplots

Answer 10

stem I leaf

Question 11

stem

Answer 11

all the numbers except the last digit

ex: 34, 3 is the stem

Question 12

leaf

Answer 12

last digit in the number

ex: 34, 4 is the leaf

Question 13

trim the leaves

Answer 13

removing the last number

ex: 235 -> 2 (stem) I 3(leaf)

Question 14

Pareto chart

Answer 14

bar graph with the largest number on the left -> smallest on the right

Question 15

population mean symbol

Answer 15

μ

Question 16

population mean equation

Answer 16

μ = Σn/n

Question 17

sample mean symbol

Answer 17

x̄

Question 18

sample mean equation

Answer 18

x̄ = Σx/n

Question 19

position of the median

Answer 19

(n+1)/2

Question 20

mode

Answer 20

highest frequency

Question 21

mean of a frequency distribution

Answer 21

x̄ = (Σx times f)/n

Question 22

mean frequency distribution explanation

Answer 22

n -> Σ(f)
x -> midpoints
f -> frequency

Question 23

symmetric distribution

Answer 23

bell shaped

Question 24

uniform

Answer 24

all equal

Question 25

skewed left

Answer 25

tail on left

Question 26

skewed right

Answer 26

tail on right

Question 27

Variability

Answer 27

how spread out a group of data is

Question 28

Range

Answer 28

highest number - lowest number

Question 29

larger range = ______ variability

Answer 29

more

Question 30

standard deviation

Answer 30

variation of the data from the mean

Question 31

σ

Answer 31

standard deviation

Question 32

population variance

Answer 32

σ^(2) = Σ(x-mean)^(2) / n

Question 33

population standard deviation

Answer 33

σ = Square root of Σ(x-mean)^(2) / n-1

Question 34

Sample variance

Answer 34

x̄^(2) = Σ(x-mean)^(2) / n

Question 35

sample standard deviation

Answer 35

x̄ = Square root of Σ(x-mean)^(2) / n-1

Question 36

empirical rule

Answer 36

68, 95, 99.7

Question 37

Chebychev’s theorem

Answer 37

1 - 1/k^2

k is standard deviation

Question 38

Coefficient variable

Answer 38

standard deviation of the data as a percentage of the mean

Question 39

Coefficient variable equation

Answer 39

(standard deviation / mean) times 100

Question 40

interquartile range (IQR)

Answer 40

Q3 - Q1

Question 41

Outliers

Answer 41

• Less than Q1 - 1.5(IQR)

- Greater than Q3 + 1.5(IQR)

Question 42

Percentile of x

Answer 42

(# of data less than x / total # of data) times 100

Question 43

standardization formula

Answer 43

z score = (x-mean)/standard deviation

Question 44

in calculator: standard deviation is ___

Answer 44

sx

Question 45

in calculator: mean is ____

Answer 45

x̄