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Finding the Fourth Proportional to 431.40, 647.10 and 402.60

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Solution

The fourth proportional to 431.40, 647.10 and 402.60 is: 603.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.40 : 647.10 = 402.60 : x
  2. Step 2: Convert to fraction form
    431.40/647.10 = 402.60/x
  3. Step 3: Cross multiply
    431.40x = 647.10 × 402.60
  4. Step 4: Simplify right side
    431.40x = 260,522.46
  5. Step 5: Solve for x
    x = 260,522.46/431.40
  6. Step 6: Final answer
    x = 603.90

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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.