Total number of washers that were checked = 2940
Number of defective washers = 588
Probability of a washer being defective can be calculated as:
P(defective) = (Number of defective Washer) / (Total Number of Washers)
Using the values we get:
P(defective) = 588/2940
P(defective) = 1/5 = 0.2
Since, the figures given are the results of an actual experiment/survey, the resulting probability will be the experimental probability.
Thus, the experimental probability of a washer being defective is 0.2