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Finding the Fourth Proportional to 718.31, 991.27 and 423.78

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Solution

The fourth proportional to 718.31, 991.27 and 423.78 is: 584.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.31 : 991.27 = 423.78 : x
  2. Step 2: Convert to fraction form
    718.31/991.27 = 423.78/x
  3. Step 3: Cross multiply
    718.31x = 991.27 × 423.78
  4. Step 4: Simplify right side
    718.31x = 420,077.21
  5. Step 5: Solve for x
    x = 420,077.21/718.31
  6. Step 6: Final answer
    x = 584.81

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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.