Practicing Averages in Biology

In a biology experiment, a student measures the growth of a plant over 5 days.

The heights recorded in centimeters are: 10, 12, 14, 13, and 11.

What is the average height of the plant over these 5 days?

• 11 cm

• 12 cm

• 13 cm

• 14 cm

Answer explanation

10+12+14+13+11= 60

60 divided by 5 = 12

The average height is 12 cm.

A biologist is studying the average number of leaves on a particular species of tree. She counts the number of leaves on 4 different trees and records the following numbers: 50, 55, 60, and 65.

What is the average number of leaves per tree?

• 55

• 57.5

• 60

• 62.5

Answer explanation

50+55+60+65=230

230 divided by 4 = 57.5

The average is 57.5 leaves per tree.

During a field study, a group of students records the number of insects found in 6 different locations: 8, 10, 12, 14, 16, and 18.

What is the average number of insects per location?

• 12

• 13

• 14

• 15

Answer explanation

8+10+12+14+16+18= 78

78 divided by 6 = 13

The average is 13 insects per location.

A researcher is analyzing the average weight of a sample of mice.

The weights in grams are: 20, 22, 24, 26, and 28.

What is the average weight of the mice?

• 22 g

• 24 g

• 25 g

• 26 g

Answer explanation

20+22+24+26+28= 120

120 divided by 5 = 24

The average weight is 24 grams.

In a study of bird populations, a scientist records the number of birds seen in 5 different areas: 15, 18, 20, 22, and 25.

What is the average number of birds observed per area?

• 18

• 20

• 21

• 22

Answer explanation

15+18+20+22+25= 100

100 divided by 5 = 20

The average is 20 birds.

A botanist is studying the average number of petals on a flower species.

She counts the petals on 5 flowers and records: 5, 7, 6, 8, and 9.

What is the average number of petals per flower?

• 9

• 8

• 7

• 6

Answer explanation

5+7+6+8+9= 35

35 divided by 5 = 7

The average is 7 petals per flower.

In a marine biology study, a scientist measures the length of 4 different fish in centimeters: 30, 35, 40, and 45.

What is the average length of the fish?

• 35 cm

• 37.5 cm

• 40 cm

• 42.5 cm

Answer explanation

30+35+40+45 = 150

150 divided by 4 = 37.5

The average is 37.5 cm.

During a wildlife survey, a team records the number of mammals spotted in 3 different regions: 12, 15, and 18.

What is the average number of mammals observed per region?

• 18

• 15

• 16.5

• 13

Answer explanation

12+15+18 = 45

45 divided by 3 = 15

The average is 15 mammals.

In a study of amphibian populations, a researcher records the number of frogs in 4 different ponds: 25, 30, 35, and 40.

What is the average number of frogs per pond?

• 30

• 32.5

• 37.5

• 35

Answer explanation

25+30+35+40= 130

130 divided by 4 = 32.5

The average is 32.5 frogs per pond.

A scientist is measuring the average temperature of a lake over 5 days.

The temperatures recorded in degrees Celsius are: 15, 17, 16, 18, and 19.

What is the average temperature of the lake?

• 19°C

• 16°C

• 17°C

• 18°C

Answer explanation

15+17+16+18+19= 85

85 divided by 5 = 17

The average temperature is 17 degrees Celsius.