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Finding the Fourth Proportional to 391.43, 539.84 and 316.70

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Solution

The fourth proportional to 391.43, 539.84 and 316.70 is: 436.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.43 : 539.84 = 316.70 : x
  2. Step 2: Convert to fraction form
    391.43/539.84 = 316.70/x
  3. Step 3: Cross multiply
    391.43x = 539.84 × 316.70
  4. Step 4: Simplify right side
    391.43x = 170,967.09
  5. Step 5: Solve for x
    x = 170,967.09/391.43
  6. Step 6: Final answer
    x = 436.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.