Finding the Fourth Proportional to 81.12, 112.08 and 77.08
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Solution
The fourth proportional to 81.12, 112.08 and 77.08 is: 106.50
Step by Step Solution
- Step 1: Write the proportion equation
81.12 : 112.08 = 77.08 : x - Step 2: Convert to fraction form
81.12/112.08 = 77.08/x - Step 3: Cross multiply
81.12x = 112.08 × 77.08 - Step 4: Simplify right side
81.12x = 8,639.13 - Step 5: Solve for x
x = 8,639.13/81.12 - Step 6: Final answer
x = 106.50
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Why These Related Problems?
These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.