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
To find the approximate number of spheres in the bag, we can use the frequency of spheres pulled out in the 20 trials and set up a proportion.
(8 spheres / 20 trials) = (x spheres / 200 total shapes)
Solving for x, we get:
x = (8/20) * 200
x = 8 * 10
x = 80
Therefore, based on the results in the table, about 80 of the shapes in the bag are spheres. The answer is C.