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Finding the Fourth Proportional to 806.20, 1,112.75 and 557.80

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Solution

The fourth proportional to 806.20, 1,112.75 and 557.80 is: 769.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.20 : 1,112.75 = 557.80 : x
  2. Step 2: Convert to fraction form
    806.20/1,112.75 = 557.80/x
  3. Step 3: Cross multiply
    806.20x = 1,112.75 × 557.80
  4. Step 4: Simplify right side
    806.20x = 620,691.95
  5. Step 5: Solve for x
    x = 620,691.95/806.20
  6. Step 6: Final answer
    x = 769.90

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1.5x scale

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.