1. **Stating the problem:** We need to find the 75th percentile (P75) of the given data set: 70, 85, 90, 75, 80, 95, 85, 70, 80, 90.
2. **Sort the data in ascending order:**
$$70, 70, 75, 80, 80, 85, 85, 90, 90, 95$$
3. **Formula for percentile position:**
$$P_k = \frac{k}{100} \times (n + 1)$$
where $k=75$ and $n=10$ (number of data points).
4. **Calculate the position:**
$$P_{75} = \frac{75}{100} \times (10 + 1) = 0.75 \times 11 = 8.25$$
5. **Interpret the position:** The 75th percentile lies between the 8th and 9th data points.
6. **Find the values at positions 8 and 9:**
8th value = 90
9th value = 90
7. **Calculate the 75th percentile by interpolation:**
$$P_{75} = x_8 + 0.25 \times (x_9 - x_8) = 90 + 0.25 \times (90 - 90) = 90$$
8. **Final answer:** The 75th percentile (P75) of the data is **90**.
Percentile 75 1Bdbfe
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