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Finding the Fourth Proportional to 497.71, 686.85 and 287.90

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Solution

The fourth proportional to 497.71, 686.85 and 287.90 is: 397.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    497.71 : 686.85 = 287.90 : x
  2. Step 2: Convert to fraction form
    497.71/686.85 = 287.90/x
  3. Step 3: Cross multiply
    497.71x = 686.85 × 287.90
  4. Step 4: Simplify right side
    497.71x = 197,748.47
  5. Step 5: Solve for x
    x = 197,748.47/497.71
  6. Step 6: Final answer
    x = 397.32

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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.