24.4 Averages from frequency tables — Practise

1. Values 1, 2, 3 have frequencies 2, 3, 1. Find the mean.

Answer: Mean $=11/6$.

2. Values 2 and 5 have frequencies 3 and 2. Find the median.

Answer: Ordered values: 2, 2, 2, 5, 5. Median $=2$.

3. Values 4, 6 and 8 have frequencies 2, 5 and 1. Find the mode.

Answer: Mode $=6$ because it has the greatest frequency.

4. Values 3, 7 and 9 have frequencies 4, 2 and 1. Find the range.

Answer: Range $=6$.

5. Values 10 and 20 have frequencies 3 and 2. Find the mean.

Answer: Mean $=14$.

6. Values 0, 1, 2 have frequencies 1, 4, 3. Find the mean.

Answer: Mean $=5/4$.

7. Values 1 and 4 have frequencies 2 and 2. Find the median.

Answer: Middle pair is 1 and 4. Median $=2.5$.

8. Values 12, 15 and 18 have frequencies 2, 7 and 1. Find the range.

Answer: Range $=6$.

9. Values 2 and 8 occur 3 and 1 times. Find the mean and compare it with the median.

Answer: Mean $=3.5$. Ordered data are 2, 2, 2, 8; median $=2$.