 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum  MENU         A B C D Solutions for Session 9, Part A

See solutions for Problems: A1 | A2    Problem A1

Sample A:
This sample of one sub-region shows five penguins: Based on this limited information, you might guess that each and every sub-region contains five penguins. Since there are 100 sub-regions, your estimate of the total number of penguins would be 100 x 5 = 500.

Sample B:
This sample of two sub-regions contains 5 + 6 = 11 penguins, or an average of 11/2 penguins per sub-region: Based on this limited information, you might guess that the average for all 100 sub-regions is 11/2 penguins. Since there are 100 sub-regions, your estimate of the total number of penguins would be 100 x (11/2) = 550.

Sample C:
This sample of three sub-regions contains 5 + 6 + 3 = 14 penguins, or an average of 14/3 penguins per sub-region: Based on this limited information, you might guess that the average for all 100 sub-regions is 14/3 penguins. Since there are 100 sub-regions, your estimate of the total number of penguins would be 100 x (14/3) = 1,400/3, or, to the nearest penguin, 467 penguins.

Here is the completed table:  Sample Photo 1 Photo 2 Photo 3 Estimate of Total  A 5 N/A N/A 500 B 5 6 N/A 550 C 5 6 3 467    Problem A2 First, find the average number of penguins in each sub-region of the sample. The total number of penguins is 5 + 6 + 6 + 7 + 5 + 2 + 1 + 5 + 5 + 3 = 45. Since there are 10 sub-regions in the sample, the average number of penguins is 45/10. Therefore, a good estimate for the total number of penguins is 100 x 45/10 = 450 penguins.     © Annenberg Foundation 2017. All rights reserved. Legal Policy