Mathematics
Using short cut method, compute the mean height from the following frequency distribution :
| Height (in cm) | Number of plants |
|---|---|
| 58 | 15 |
| 60 | 14 |
| 62 | 20 |
| 65 | 18 |
| 66 | 8 |
| 68 | 5 |
Measures of Central Tendency
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Answer
Let assumed mean (A) = 62.
| Height (x) | Number of plants (f) | d = x - A | fd |
|---|---|---|---|
| 58 | 15 | -4 | -60 |
| 60 | 14 | -2 | -28 |
| A = 62 | 20 | 0 | 0 |
| 65 | 18 | +3 | 54 |
| 66 | 8 | +4 | 32 |
| 68 | 5 | +6 | 30 |
| Total | ∑ f = 80 | ∑fd = 28 |
We know that,
n = ∑f = 80.
By formula,
Hence, mean height of the plants is 62.35 cm.
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