Question

A quality controller inspected 500 units of a product and rejected 80 units due to defects. What is the probability that a unit will pass inspection (no defects)?(1 point)
Responses

50%
50%

0%
0%

84%
84%

16%

Answer 1

To find the probability that a unit will pass inspection (i.e., has no defects), we first need to determine how many units passed inspection.

The total number of units inspected is 500, and 80 units were rejected due to defects. Therefore, the number of units that passed inspection is:

\[
500 - 80 = 420
\]

Now, the probability \( P \) that a unit will pass inspection is given by the ratio of the number of units that passed to the total number of units inspected:

\[
P(\text{pass}) = \frac{\text{Number of units that passed}}{\text{Total number of units}} = \frac{420}{500}
\]

Calculating this gives:

\[
P(\text{pass}) = \frac{420}{500} = 0.84
\]

To express this as a percentage, we multiply by 100:

\[
0.84 \times 100 = 84\%
\]

Thus, the probability that a unit will pass inspection (no defects) is **84%**.