Question

A quality control expert randomly samples 60 pairs of sunglasses and finds 5 defective pairs. predict how many defective pairs will be in a shipment of 420 sunglasses.

Answer 1

420/60=7
7*5=35 sunglasses

Answer 2

For this case the first thing you should do is find the percentage of sunglasses that are defective.

For this, we make the following rule of three:

60 pairs -------------------> 100%

5 pairs ---------------------> x

From here, we clear the value of x.

We have then:

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We now look for the amount of sunglasses that may come with defects.

We have then:

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Rounding to the nearest whole number:

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Answer:

About 35 defective pairs will be in a shipment of 420 sunglasses