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Finding the Fourth Proportional to 781.52, 1,078.60 and 471.20

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Solution

The fourth proportional to 781.52, 1,078.60 and 471.20 is: 650.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.52 : 1,078.60 = 471.20 : x
  2. Step 2: Convert to fraction form
    781.52/1,078.60 = 471.20/x
  3. Step 3: Cross multiply
    781.52x = 1,078.60 × 471.20
  4. Step 4: Simplify right side
    781.52x = 508,236.32
  5. Step 5: Solve for x
    x = 508,236.32/781.52
  6. Step 6: Final answer
    x = 650.32

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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.