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Finding the Fourth Proportional to 457.60, 686.40 and 405.40

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Solution

The fourth proportional to 457.60, 686.40 and 405.40 is: 608.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.60 : 686.40 = 405.40 : x
  2. Step 2: Convert to fraction form
    457.60/686.40 = 405.40/x
  3. Step 3: Cross multiply
    457.60x = 686.40 × 405.40
  4. Step 4: Simplify right side
    457.60x = 278,266.56
  5. Step 5: Solve for x
    x = 278,266.56/457.60
  6. Step 6: Final answer
    x = 608.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.