Understanding Percentages and Averages

Which of the following is the correct formula to calculate percent change between an original value and a new value?

Given the data set: 4, 7, 9, 10, 15, what is the mean?

• 7

• 9

• 10

• 15

What is the range of the following data set: 3, 8, 12, 15, 20?

• 17

• 12

• 15

• 20

If a pie chart represents a total of 200 students and 50 students prefer science, what percent slice of the pie chart does science represent?

• 10%

• 20%

• 25%

• 50%

A student records the following measurements: 12.3 cm, 12.35 cm, and 12.4 cm. If the measuring instrument is accurate to the nearest 0.1 cm, how many significant figures should the average be reported with?

• 2

• 3

• 4

• 5