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GB-31-03-001 · Mean from a frequency table

The table shows the number of pets owned by some students.

Pets01234
Frequency813545
Calculate the mean number of pets. Give your answer to 2 decimal places.

Averages: Mean from an Ungrouped Frequency Table Booklet p. 67
Method
1) Use the actual value x for ungrouped data; use a midpoint only for a class interval
2) Multiply each value by its frequency
3) Divide the total fx (or fm) by the total frequency
Worked Example (GB-31-03-001)
1)
Pets xFrequency ffx
080
11313
2510
3412
4520
Total3555
2)
Mean=∑fx∑f=5535=1.57\text{Mean}=\frac{\sum fx}{\sum f}=\frac{55}{35}=1.57
Ans = 1.57