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Finding the Fourth Proportional to 431.70, 648.08 and 429.72

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Solution

The fourth proportional to 431.70, 648.08 and 429.72 is: 645.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.70 : 648.08 = 429.72 : x
  2. Step 2: Convert to fraction form
    431.70/648.08 = 429.72/x
  3. Step 3: Cross multiply
    431.70x = 648.08 × 429.72
  4. Step 4: Simplify right side
    431.70x = 278,492.94
  5. Step 5: Solve for x
    x = 278,492.94/431.70
  6. Step 6: Final answer
    x = 645.11

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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.