 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum  MENU          Session 9, Part C:
Investigating Variation in Estimates (45 minutes)

In This Part: Using a Stem and Leaf Plot | Judging the Quality of Estimates | Intervals
Describing Intervals | Probabilities

In Part B, you obtained several different estimates for the total number of penguins in this region based on the different samples you chose. Note 5

We can use a stem and leaf plot to help us organize the estimates and to determine any patterns that exist in the distribution of the estimates.

In the manner you used to generate your own estimates, 100 estimates of the penguin population count were produced from independently selected random samples of size 10. Here are these 100 estimates in a stem and leaf plot, where the intervals are of size 50: Note that in this stem and leaf plot, the spacing on the stems is 50. For example, the stem marked "3L" displays all the estimates between 300 and 349, while the stem marked "3H" displays all the estimates between 350 and 399. Also, since the samples are of size 10, all the estimates are multiples of 10.  Problem C1 a. Based on the stem and leaf plot of these 100 estimates, make a guess for the actual number of penguins in the region. b. Give an interval of values in which you are fairly certain the actual number of penguins in the region lies. (This interval should include the guess you made in the question above!)  The interval should include most of the data in the stem and leaf plot. For example, "between 200 and 400" would be a very poor interval of values.   Close Tip The interval should include most of the data in the stem and leaf plot. For example, "between 200 and 400" would be a very poor interval of values.   Session 9: Index | Notes | Solutions | Video

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