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Finding the Fourth Proportional to 807.92, 1,115.40 and 513.20

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Solution

The fourth proportional to 807.92, 1,115.40 and 513.20 is: 708.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.92 : 1,115.40 = 513.20 : x
  2. Step 2: Convert to fraction form
    807.92/1,115.40 = 513.20/x
  3. Step 3: Cross multiply
    807.92x = 1,115.40 × 513.20
  4. Step 4: Simplify right side
    807.92x = 572,423.28
  5. Step 5: Solve for x
    x = 572,423.28/807.92
  6. Step 6: Final answer
    x = 708.51

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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.