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Finding the Fourth Proportional to 431.22, 645.32 and 309.72

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Solution

The fourth proportional to 431.22, 645.32 and 309.72 is: 463.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.22 : 645.32 = 309.72 : x
  2. Step 2: Convert to fraction form
    431.22/645.32 = 309.72/x
  3. Step 3: Cross multiply
    431.22x = 645.32 × 309.72
  4. Step 4: Simplify right side
    431.22x = 199,869.28
  5. Step 5: Solve for x
    x = 199,869.28/431.22
  6. Step 6: Final answer
    x = 463.50

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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.