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Finding the Fourth Proportional to 646.31, 892.10 and 380.78

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Solution

The fourth proportional to 646.31, 892.10 and 380.78 is: 525.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.31 : 892.10 = 380.78 : x
  2. Step 2: Convert to fraction form
    646.31/892.10 = 380.78/x
  3. Step 3: Cross multiply
    646.31x = 892.10 × 380.78
  4. Step 4: Simplify right side
    646.31x = 339,691.93
  5. Step 5: Solve for x
    x = 339,691.93/646.31
  6. Step 6: Final answer
    x = 525.59

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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.