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Finding the Fourth Proportional to 872.43, 1,308.07 and 287.20

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Solution

The fourth proportional to 872.43, 1,308.07 and 287.20 is: 430.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.43 : 1,308.07 = 287.20 : x
  2. Step 2: Convert to fraction form
    872.43/1,308.07 = 287.20/x
  3. Step 3: Cross multiply
    872.43x = 1,308.07 × 287.20
  4. Step 4: Simplify right side
    872.43x = 375,677.70
  5. Step 5: Solve for x
    x = 375,677.70/872.43
  6. Step 6: Final answer
    x = 430.61

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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.