Quarter 1 Mathematics 8 Review Quiz

Which of the following is the median of the data set {10, 12, 20, 22, 26}?

• 10

• 12

• 15

• 20

Answer explanation

The data are already in ascending order and there are 5 values.

The median is the middle (3rd) value → 20.

What is the average height of the students given their heights (in cm) are: 150, 155, 160, 165, 170, 175, 180?

• 160

• 165

• 170

• 175

Answer explanation

What is the average height of the students given their heights (in cm) are: 150, 155, 160, 165, 170, 175, 180?

Average is also know as MEAN or the total sum of the data divided by the number of data points.

AVERAGE OR MEAN

= (150 + 155 + 160 + 165 + 170 + 175 + 180) / 7

= 1155 / 7

= 165

Which statement is TRUE about the mode?

• It is the average of all values.

• It is the value that occurs most often.

• It is the middle value when arranged.

• It is always greater than the mean.

Which statement is TRUE about the mean?

• It is the average of all values.

• It is the value that occurs most often.

• It is the middle value when arranged.

• It is always greater than the mean.

A class has the following scores: 15, 18, 20, 22, 25. Which statement is TRUE about the mean and median?

• Mean = Median

• Mean > Median

• Median > Mean

• Median < Mean

Answer explanation

Mean = Median ✅

• Median (middle of 5 ordered scores) = 20

• Mean = (15+18+20+22+25)/5

• =100/5

• =20
  So they’re equal.

A teacher recorded the English Scores of her class and found the mean score was 80, the median was 85, and the mode was 90. Based on these measures, which of the following is the most reasonable conclusion?

• Most students scored higher than the mean.

• The scores were evenly distributed

• The highest score was 90.

• Most students scored below 80.

Which expression represents the sum of twice a number and 9?

• 2x + 9

• 9 + x

• 2x - 9

• (2x) (9)

Answer explanation

“twice a number” → 2x;

“sum … 9” → add 9

→ 2x+9

Which of the following represents 'Seven less than a number'?

• x + 7

• 7 + x

• 7 - x

• x - 7

Answer explanation

Seven less than a number” means subtract 7 from the number (not the other way around).

Which of the following represents 'Eleven less a number'?

• x + 11

• 11 + x

• 11 - x

• x - 11

Answer explanation

Eleven less a number” means

subtract the number from 11

(different from “eleven less than a number,” which would be 11 - x

What is the sum of 7x and x?

• 8x

• 15x

• 9x

• 9y²

Answer explanation

Combine like terms: 7x+1x=8x