Let x be the number of defective disks.

(Number of defective compact disks in the sample) / (Total number of disks in the sample) = (Number of defective disks in a sample of 2000 disks) / (Total number of disks)

20500 = x2000

x = 20 × 2000500

= 80

Chris can expect 80 disks to be defective in a sample of 2000 disks.

Let the number of doorbells defective in a sample of 15,000 doorbells be y.

Doorbells defective in a sample of 150 doorbells / Number of doorbells = Doorbells defective in a sample of 15,000 doorbells / Number of doorbells

Number of doorbells defective in a sample of 15,000 is 600.

Let y be the number of pairs defective out of 250 pairs.

Number of pairs defective in 50Number of sample pairs = Number of pairs defective in 250Total number of pairs

1050 = y250

y = 10 × 25050

= 50

The shoe manufacturer can predict 50 pairs of defective shoes.

Let y be the number of students who like football out of 2500.

Write a proportion.

34100 = y2500

y = 2500 × 34100

= 850

850 out of 2500 students like football.

From the graph, the distance that Justin covers is increasing in each hour.

The distance that Justin covers in 15 hours is 150 mi.

So, one would expect the distance that Justin covers in 20 hours to be certainly greater than 150 mi.

Let y be the number of people who like wrestling out of 2000.

Number of people who like wrestling out of 100 people / Total number of people = Number of people who like wrestling out of 2000 people / Total number of people

460 out of a population of 2000 people like wrestling.

Let y be the number of people who like football out of 1000.

Number of people who like football out of 100 people / Total number of people = Number of people who like football out of 1000 people / Total number of people

340 out of a population of 1000 people like football.

Let x be the number of students in the entire school who prefer dance class to music class.

Total number of students in the school = 600

815 = x600⇒ x = 815 × 600 = 320

So, 320 students in the school prefer dance class to music class.

Prediction means telling what would happen in the near future.

The graph shows an increasing trend in the profit earned by a company (in percent) during the last three years by 10% .

The profit earned by the company (in percent) in the year 2004 is 50%

So, it can be predicted that the profit earned by the company(in percent) for the year 2005 would be 60% .

The sales have been decreasing each month.

Sales in the month of May are $1,000.

So, one would expect the sales in June to be less than $1,000.

From the bar graph, the difference in the population of a country in succeeding years is 50%.

So, the population in the year 2003 would be about 260 million.

The given graph shows the circulation of a magazine (in thousands) in the year 2004.

The circulation of the magazine in the first quarter of 2004 will be about 180, 000.

Among 150 people, 75 preferred rock music.

That means half of the people preferred rock music.

So, 300 people out of 600 could be predicted to prefer rock music.

Number of Toys checked = 500.

Number of Toys found to have defective = 10.

Probability of a Toys to have defective out of 100 = 10500

Number of Toys to have defective out of 200 magazines = 200 × 150

= 4.

Number of T-shirts manufactured every week = 6000.

Number of T-shirts checked = 100.

So, the probability of getting a defective T-shirt = 6100

= 350

Therefore, the number of T-shirts that can have defects in each week of the production = 6000 × 350

= 360