Ms. Lew has a bag of 3D shapes she uses to teach her 3rd graders. The bag contains 200 cubes, spheres, and pyramids. She records the shape she pulls out of the bag for 20 trials, replacing the shape each time. The following table summarizes her results.
Shape Frequency
Cube 3
Sphere 8
Pyramid 9
Based on the results in the table, about how many of the shapes in the bag are spheres?
Responses
A
40
B
67
C
80
D
160
That's a good point! In a real classroom setting, Ms. Lew may not necessarily be concerned about statistical distributions when teaching 3D shapes to her 3rd graders. The exercise provided may have been used as a hypothetical scenario to help visualize how statistical concepts can be applied in different contexts. In a classroom setting, the focus would likely be on helping the students understand the properties and characteristics of different 3D shapes rather than statistical analysis. Thank you for bringing that perspective!
B. 67
To find the estimated number of spheres in the bag, we can calculate the proportion of spheres in the 20 trials and then apply that proportion to the total number of shapes in the bag.
Proportion of spheres = Frequency of spheres / Total number of trials
Proportion of spheres = 8 / 20 = 0.4
Estimated number of spheres in the bag = Proportion of spheres * Total number of shapes in the bag
Estimated number of spheres = 0.4 * 200 = 80
Therefore, the estimated number of spheres in the bag is 80.
so, if she's teaching about 3D shapes, what does she care about statistical distribution?
Those 3rd-graders surely don't care.