Answer:
The expected number of defective batteries to be pulled out is 0.9, which rounded to the nearest integer gives a total of 1, that is, 1 of the 3 batteries is expected to be defective.
Step-by-step explanation:
Given that a box contains 3 defective batteries and 7 good ones, and I reach in and pull out three batteries, to determine what is the expected number of defective batteries, the following calculation must be performed:
3 + 7 = 100
3 = X
10 = 100
3 = X
3 x 100/10 = X
300/10 = X
30 = X
3 x 3/10 = X
0.9 = X
Therefore, the expected number of defective batteries to be pulled out is 0.9, which rounded to the nearest integer gives a total of 1, that is, 1 of the 3 batteries is expected to be defective.
