2.1 Frequency Distributions

Question 1

Frequency Distribution

Answer 1

Is a table that shows classes or intervals of data entries with a count of the number of entries in each class

Question 2

Frequency, f

Answer 2

Of a class is the number of data entries in each class

Question 3

Lower Class Limit

Answer 3

This is the least number that can belong to a class

Question 4

Upper Class Limit

Answer 4

This is the greatest number that can belong to a class

Question 5

Class Width

Answer 5

Is the distance between lower (or Upper) limits of consecutive class. Class width = (MAX - MIN)/ # of classes

Question 6

Range

Answer 6

The difference between the maximum and minimum data entries

Question 7

Find the class width:
Max = 125
Min = 67
# of classes = 5

Answer 7

11.6 rounds up to 12. The class width is 12

Question 8

Find the class width:
Max = 125
Min = 25
# of classes = 5

Answer 8

20 rounds up to 21. The class width is 21.

Question 9

Find the class width:
Max = 125
Min = 83
# of classes = 5

Answer 9

8.4 rounds up to 9. The class width is 9.

Question 10

Midpoint

Answer 10

Is the sum of the lower and upper limits of the class divided by two. Midpoint = (upper + lower)/ 2

Question 11

Relative Frequency

Answer 11

Of a class is the portion or percentage of the data that falls in that class.  
Relative Frequency = f/sum of the f.

Question 12

Cumulative Frequency

Answer 12

Of a class is the sum of the frequency for that class and all previous classes

Question 13

Frequency Histogram

Answer 13

A bar graph that represents the frequency distribution of a data set.

1. The x-axis is quantitative data values (boundaries)
2. y-axis is the frequency or relative frequency
3. Consecutive bars must touch
4. Don’t forget a jump if the graph does not start at zero
5. Don’t forget to LABEL!

Question 14

Class Boundaries

Answer 14

The numbers that separate classes without forming gaps between them
Subtract 0.5 from each lower limit and add 0.5 to each upper limit