1. **Problem statement:** We need to find a linear function that converts the highest mark 285 to 200 and the lowest mark 75 to 60.
2. **Formula and explanation:** A linear function can be written as $y = mx + c$, where $m$ is the slope and $c$ is the intercept.
3. **Find the slope $m$:** Using the two points $(285, 200)$ and $(75, 60)$,
$$m = \frac{200 - 60}{285 - 75} = \frac{140}{210} = \frac{\cancel{140}}{\cancel{210}} = \frac{2}{3}$$
4. **Find the intercept $c$:** Using $y = mx + c$ and the point $(285, 200)$,
$$200 = \frac{2}{3} \times 285 + c$$
$$200 = 190 + c$$
$$c = 200 - 190 = 10$$
5. **Linear function:**
$$y = \frac{2}{3}x + 10$$
6. **Use the function to find new marks for original marks 95, 175, 215, and 255:**
- For $x=95$:
$$y = \frac{2}{3} \times 95 + 10 = \frac{190}{3} + 10 = 63.33 + 10 = 73.33$$
- For $x=175$:
$$y = \frac{2}{3} \times 175 + 10 = \frac{350}{3} + 10 = 116.67 + 10 = 126.67$$
- For $x=215$:
$$y = \frac{2}{3} \times 215 + 10 = \frac{430}{3} + 10 = 143.33 + 10 = 153.33$$
- For $x=255$:
$$y = \frac{2}{3} \times 255 + 10 = \frac{510}{3} + 10 = 170 + 10 = 180$$
**Final answers:** The linear function is $y = \frac{2}{3}x + 10$.
The new marks corresponding to original marks 95, 175, 215, and 255 are approximately 73.33, 126.67, 153.33, and 180 respectively.
Linear Mark Conversion B17D77
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