Question

Using Proportions to Make a Prediction
Of 25 grocery store shoppers, 14 said that their family’s favorite breakfast is cereal bars. Predict how many of 500 families at grocery store would buy cereal bars.





Of 200 radio-controlled cars that were manufactured by one company, 3 were defective. The company manufactures 1000 cars each day. About how many
defective cars would you predict are produced each day?


HELP......HELP......HELP

Answer 1

○=> Solution (1) :

Ratio of people who said they like cereal bars to people who said they don't = 14:11

Number of people at a grocery shop = 500

Which means :

$=\tt \frac{14}{25} \times 500$

$=\tt \frac{14 \times 500}{25}$

$= \tt \frac{7000}{25}$

$\color{plum}= \tt280 \: people$

Thus, 280 people would buy cereal bars.

▪︎Therefore, out of 500 people, 280 people would buy cereal bars.

○=> Solution (2) :

Ratio of cars which worked well to cars which were defective = 297:3

Number of care produced each day = 1000

Number of defective cars produced each day :

$= \tt \frac{3}{200} \times 1000$

$=\tt \frac{3 \times 1000}{200}$

$= \tt\frac{3000}{200}$

$\color{plum} = \tt15 \: defective \: cars$

Thus, 15 defective cars are produced.

▪︎Therefore, out of 1000 cars produced each day, 15 cars are defective.