Answer:
Monday: 4 hours = $36
Tuesday: 6 hours = $54
Wednesday: 5 hours = $45
His earnings are proportional because, for each hour, Richard earns $9. Using the formula y = kx, k (the constant) is always the same:
- 36 = k × 4 (k = $9)
- 54 = k × 6 (k = $9)
- 45 = k × 5 (k = $9)
Hope this helps!