Chapter 2: Data

Question 1

Data List

Answer 1

an explicit listing of all the individual measurements made on a sample

Question 2

data frequency table

Answer 2

a table listing each individual value of x and its frequency

Question 3

Frequency of a value

Answer 3

number of times it appears in the sample data

Question 4

Sturge’s Rule

Answer 4

desirable number of classes = 1 + 3.3log(n)

Question 5

sample size

Answer 5

number of individuals in the sample

Question 6

(absolute) class frequency

Answer 6

number of measurements in the data set that are in each class

Question 7

(absolute) frequency distribution

Answer 7

table form summary that shows the class frequency for each class

Question 8

relative frequency

Answer 8

proportion of all measurements in the data set that are in the class

Question 9

relative frequency distribution

Answer 9

table summary of a data set that shows the relative frequency for each class

Question 10

cumulative class frequency

Answer 10

sum of all class frequencies

Question 11

Non-probability sample

Answer 11

sample taken in a haphazard fashion without the use of some randomizing device assigning each member a known probability of selection

Question 12

probability sample

Answer 12

sample taken with the help of a randomizing device that assures each member a known probability of selection

Question 13

random sample

Answer 13

sample obtained using a randomizing device that assures each member of the population has an equal chance of being selected for the sample

Question 14

Sample Mean (X bar)

Answer 14

Sum of x / n

Question 15

Population mean (μ)

Answer 15

sum of X / N

Question 16

sample median

Answer 16

odd number of measurements: in the middle

even number of measurements: mean of the middle two

Question 17

Sample Variance

Answer 17

sum (x - xbar)^2 / n - 1

Question 18

Skewness of a data set

Answer 18

measure of the frequency distributions deviation from symmetry

Question 19

kurtosis of a data set

Answer 19

measure of the heavy tailedness of its frequency distribution

Question 20

coefficient of variation

Answer 20

ratio of the SD to the Mean

Question 21

Sample Proportion

Answer 21

frequency of observations (in a particular category) / n