If 0.25a = 0.05b, then which of the options below gives the best approximation of the value of \( \frac{b-a}{b+a} \)?
Find the missing value of weight (X) assigned if the weighted average of the data set provided below is 24.5.
| Object | A | B | C | D |
| Value of object | 15 | 2 | 30 | 43 |
| Assigned weight | 3 | 2 | x | 1 |