Question

A quality control technician checked a sample of 30 bulbs. Two of the bulbs were defective. If the sample was representative, find the number of bulbs expected to be defective in a case of 450.

Answer 1

30

Explanation:

2 out of 30 were defective. The percentage rate is found by dividing 2 by 30 and then multiplying by 100, so that would be:

Percentage Defective Rate = 2/30 * 100 = 6.67%

Now, we have to find the expected defective number of bulbs in a total of 450. So we find 6.67% of those. That would be the decimal (0.0667) multiplied by 450:

0.0667 * 450 = 30

So, out of 450 bulbs, 30 would be expected to be defective

Answer 2

30

Explanation:

2 out of 30 were defective. The percentage rate is found by dividing 2 by 30 and then multiplying by 100, so that would be:

Percentage Defective Rate = 2/30 * 100 = 6.67%

Now, we have to find the expected defective number of bulbs in a total of 450. So we find 6.67% of those. That would be the decimal (0.0667) multiplied by 450:

0.0667 * 450 = 30

So, out of 450 bulbs, 30 would be expected to be defective