Find the mode, range and mean of data sets!
The mode is the value that appears most often in a data set.
Example: 3, 5, 3, 7, 3, 9 → 3 appears 3 times → mode = 3
A data set can have more than one mode (bimodal) or no mode.
The range measures the spread of data.
Example: {5, 8, 2, 10} → range = 10 − 2 = 8
A small range means the data is close together. A large range means it is spread out.
The mean (arithmetic average) is found by dividing the total by the number of values.
Example: {2, 4, 6} → sum = 12, count = 3 → mean = 12 ÷ 3 = 4
If you know the mean and all values except one:
Example: mean = 5, n = 4, known values {3, 5, 7, ?}
Sum needed = 5 × 4 = 20. Known sum = 3+5+7 = 15. Missing = 20−15 = 5
Decide which average is needed:
| Measure | Tells you |
|---|---|
| Mode | Most popular / most common |
| Range | How spread out the data is |
| Mean | Fair share / typical value |
Find the mode of: 8, 2, 8, 5, 8, 3
Find the range of: {12, 6, 9, 15}
Find the mean of: {3, 5, 7, 9}
Mean = 6, n = 3, data = {4, 8, ?}
Find the mode of each data set.
Find the range of each data set.
Find the mean of each data set.
Find the missing value to achieve the given mean.
Solve each problem about averages.