2.1-2.2 Probability and Stat. Review

This is the interval between two consecutive upper (or lower) class limits.

• class width

• class boundaries

• midpoints

• frequency

Why is this frequency distribution incorrect?

• The fourth class width is different from the others

• There is a zero.

• Classes should overlapped.

Find the midpoints.

• 25.5, 35.5, 45.5, 55.5, 65.5, 75.5

• 20.5, 30.5, 40.5, 50.5, 60.5, 70.5, 80.5

• 21, 31, 41, 51, 61, 71

• 30, 40, 50, 60, 70, 80

Find the relative frequencies

• 37%, 76%, 92%, 95%, 98%, 100%

• 28%, 30%, 12%, 2%, 2%, 2%

• 33%, 37%, 20%, 7%, 7%, 7%

• 37%, 39%, 16%, 3%, 3%, 3%

Find the cumulative frequencies.

• 28, 56, 84, 100

• 28, 58, 70, 72, 74, 76

• 33%, 37%, 20%, 7%, 7%, 7%

• 28, 30, 12, 2, 2, 2

Look at the frequency distribution. Find the class boundaries.

• 21, 31, 41, 51, 61, 70, 80

• 25.5, 35.5, 45.5, 55.5, 65.5, 75.5

• 20.5, 30.5, 40.5, 50.5, 60.5, 70.5

• 30, 40, 50, 60, 70, 80

What would be the cumulative frequency for the third class?

• 5

• 12

• 17

• 18

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

• Frequency distribution
• Frequency polygon
• Histogram
• Ogive

Is a histogram the same as a bar graph?

• Yes, because they both use intervals.
• No, because a histogram displays numerical data while a bar graph displays categorical data.
• Yes, because they both use bars to display data.
• No, because a histogram displays categorical data while a bar graph displays numerical data.

What is another name for the ogive?

• Histogram

• Frequency Polygon

• Cumulative frequency graph

• Pareto chart