1. Samples & Populations 1.3
Learning Target: I will distinguish
categorical data from numerical data.
Homework Inv 1 Day 3: SP 1.3 p. 13 – Using Spread and Center and CORRECT w/ EDpuzzle Warm Up:
1. How many data values are within one MAD of the mean? 2. within two MADs?
(above or below)
Write this number as a percent =

2. Warm Up
How many data values are within one MAD of the mean? (above or below)
Write this number as a percent =
10.6 to = 16 values/30 values
53.3%
How many data values are within two MADs of the mean? (above or below)
Write this number as a percent =
8.77 to 16.09= 29values/ 30 values
96.6%

3. Information sorted into categories or groups.
Categorical Data
Numerical Data
Information sorted into categories or groups.
(favorite movies, eye colors, birth months, etc.)
Data which involves counting or measuring. (Numbers)
Frequency: The number of times a specific data value occurs in a data set. (7,7,3,4,5,2: the frequency of 7’s in this set is “2.” The frequency of 4 is “1.”)

7. How do you find relative frequencies?
p. 11
The sample sizes of Internet respondents and 7th graders are different. You can use relative frequencies – frequencies based on percentages – to compare samples of different sizes.
How do you find relative frequencies?
Ex: What is the frequency of people who prefer to sit on the front of the roller coaster in each sample?

8. 97 27 50 22 18 14 165 63 Roller Coaster Seating Preferences Front
Votes from Internet
Relative Frequency
Votes from
7th Graders
Votes From Our Class
Front 97 27
Middle 50 22
Back 18 14
Total Votes
165 63

9. Other Roller Coaster Preferences
Votes from Internet
Relative Frequency
Votes from
7th Graders
Votes from Our Class
Airtime 88 31
Height 36 24
Inversion 59 29
Smooth-ness 39 12
Speed
105 57
Total Votes
327
153

10. Our Math Class
_____ respondents

11. Which of the following roller coaster characteristics do you prefer
Which of the following roller coaster characteristics do you prefer? You may choose more than one.
Math Class
_____ respondents
The mode can be used to describe these results because it is a measure of center for categorical (nominal) data.

12. Most people like speed when they ride a coaster.
Question One:
First seating choice?
Last seating choice?
Online vs. 7th graders vs. class?
Question Two:
Strongest preference?
Least important?
Online vs. 7th graders vs. class?
Most people surveyed like to ride at the front, although 7th graders like to ride the middle almost as much as the front.
Most people like speed when they ride a coaster.
- Summaries are helpful in order to make general conclusions about the data, although these are just samples.

13. About 200 people would prefer to sit in front.
Votes from the web = about 59%
Votes from the 7th graders = about 43%
This averages to about 50%.

14. Samples & Populations 1.3
Did I reach my Learning Target?
I will distinguish categorical data from numerical data.
Homework Inv 1 Day 3: SP 1.3 p. 13 – Using Spread and Center and CORRECT w/ EDpuzzle