4. Day 2 Random Samples.notebook March 06, 2013
Anticipatory Set
What proportion of students in Great Hollow Middle
School chooses football as their favorite sport?
1.) How would you collect your data to come to a
conclusion on this survey question?
2.) Will your results be the same as all the other
students in this class?
4
8. Day 2 Random Samples.notebook March 06, 2013
Defective Products: An automobile brake pad
assembly line find that 6% of its brake pads are
defective.
1.) If I take a random sample of 200 brake pads,
how many would I expect to be defective?
2.) Suppose I took a different random sample of
200 and found that 15 were defective. What
percent is defective in my random sample?
3.) Suppose I took another random sample of 10
brake pads and found that none were defective.
How is that possible?
8
9. Day 2 Random Samples.notebook March 06, 2013
Random Number Generator:
Values 1 to 100 represent a defective product and values 101
to 1000 represent a non‐defective product.
Sample size 10
Defective Non Defective
9
10. Day 2 Random Samples.notebook March 06, 2013
Random Number Generator:
Values 1 to 100 represent a defective product and values 101
to 1000 represent a non‐defective product.
Sample size 30
Defective Non Defective
10
11. Day 2 Random Samples.notebook March 06, 2013
Random Number Generator:
Values 1 to 100 represent a defective product and values 101
to 1000 represent a non‐defective product.
Sample size 30
Defective Non Defective
11
12. Day 2 Random Samples.notebook March 06, 2013
Before You Leave
1.) Was the percent of defective
products the same for all our sample?
2.) How did the sample size 10 results
compare to the sample size 30?
12
