Comparative Inferences- Populations

Comparative Inferences- Populations

Example 1

Quinn collects data from a random sample of 20 seventh grade students in a fitness program. She compares the number of curl ups from last year to this year. What can she infer from her comparison?

Step 1- Display Data in a dot plot

Multiple Choice

What do the dots in the dot plot represent?

• Each dot is one student

• The number of curl ups

Step 2- Use the dot plot to compare

Multiple Choice

What is the range of data set?

• 5

• 7

• 4

Multiple Choice

What is mode?

• Middle number

• The average of the data

• The most common number

Multiple Choice

What is the mode of this data?

• 23

• 24

• 20

Let's Review

The range is 7

The mode is 24

Now, let's look at the next set of data...

Multiple Choice

What is the range of the data?

• 9

• 7

• 3

Multiple Choice

What is the mode of the data?

• 28

• 24

• 27

Let's compare

What can we infer?

Multiple Choice

What would be a good inference based on our data?

• Most students were able to do LESS curl ups this year.

• Most students were able to do MORE curl ups this year.

• There is not enough data.

Now you try!

What inference can you make about the number of pushups?

Open Ended

Type your inference based off of the dot plot

MAD

• Mean of the distances of each value from the mean of the data set

• Find how far each data point is from mean, add together and divide by data points

MAD for Curl Ups

• Which set has a greater MAD?

• Curl Ups this year

• What does that tell us?

• Not all students made the same progress- more variation in the data

Use stats to make a prediction!

• Quinn's classmate tells her the number of curl ups he completed this year and last.

• He did not tell Quinn which year was which

• 
  

Multiple Choice

Based on what we know about the curl ups, what number of curl ups did he complete THIS year?

• 19

• 23

Open Ended

Use the data from the chart. Calculate the mean for week 1 and week 2. Type your answer like this.... Week 1 mean=.... Week 2 mean=....

What inference can we make about the team from our data?