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Finding the Fourth Proportional to 781.81, 1,078.65 and 471.31

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Solution

The fourth proportional to 781.81, 1,078.65 and 471.31 is: 650.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.81 : 1,078.65 = 471.31 : x
  2. Step 2: Convert to fraction form
    781.81/1,078.65 = 471.31/x
  3. Step 3: Cross multiply
    781.81x = 1,078.65 × 471.31
  4. Step 4: Simplify right side
    781.81x = 508,375.83
  5. Step 5: Solve for x
    x = 508,375.83/781.81
  6. Step 6: Final answer
    x = 650.26

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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.