Question

A cell phone company orders 300 new phones from a manufacturer. If the probability of a phone being defective is 3.5%, predict how many of the phones are likely to be defective. Round to the nearest whole number.

Answer 1

10 phones out of 300
300 x 0.035 = 10.5 =10

Answer 2

For this case we can make the following rule of three:

300 phones ----------------> 100%

x ----------------------------------> 3.5%

From here, we clear the value of x.

We have then:

`x = (\frac {3.5} {100}) (300)\\x = 10.5`

Rounding to the nearest whole number:

`x = 11`

Answer:

11 of the phones are likely to be defective