Distance Weighed Average
1. Problem 6: On a map, 1 inch represents 20 miles. The distance between 2 towns is 6\frac{1}{5} inches. Find the actual distance in miles.
2. Convert mixed fraction 6\frac{1}{5} to improper fraction:
$$6\frac{1}{5} = \frac{31}{5}$$
3. Calculate actual distance by multiplying map distance by scale:
$$\text{Distance} = \frac{31}{5} \times 20 = \frac{31 \times 20}{5} = \frac{620}{5} = 124$$ miles
4. So, the actual distance between the two towns is 124 miles.
5. Problem 7: Calculate weighted average of student marks with weights: Mathematics 3, English 3, History 2, Science 2, Art 1.
6. Given marks:
- Geometry (Math): 89
- American Literature (English): 92
- American History (History): 94
- Biology (Science): 81
- Sculpture (Art): 85
7. Multiply each mark by its weight:
$$89 \times 3 = 267$$
$$92 \times 3 = 276$$
$$94 \times 2 = 188$$
$$81 \times 2 = 162$$
$$85 \times 1 = 85$$
8. Sum weighted scores:
$$267 + 276 + 188 + 162 + 85 = 978$$
9. Sum of weights:
$$3 + 3 + 2 + 2 + 1 = 11$$
10. Calculate weighted average:
$$\frac{978}{11} = 88.91$$ (rounded to two decimals)
Hence, the student's weighted average is approximately 88.91.