Question

In a batch of 890 calculators, 12 were found to be defective. What is the probability that a calculator chosen at random will be defective? Write the probability as a percent. Round to the nearest thence of a percent of necessary.

Answer 1

1.3%

Explanation:

First set this up as the proportion

Is over of equals percent over 100

We put x as the percent because that's what were trying to figure out

is/of = x/100

Since there are only two numbers in the problem it will be easier to find out what numbers are the is and the of.

The problems says 12 out of 890 calculators are defective. So 890 will be our of and 12 will be the is

So 12/890 = x/100

Now we have to do Cross Product Property

So 12*100 = 1200

890*x = 890x

890x = 1200

Then you have to solve for x by dividing 1200 by 890, which is 1.3483%

Now round 1.3483% to the tenth of a percent

1.3%

Answer 2

1.3%

When entered into a calculator, 12/890 (the chance of a given calculator being defective) = 0.01348...

As a percent this is 100*0.01348% = 1.348%, and to the nearest tenth, 1.3%