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Finding the Fourth Proportional to 718.20, 991.21 and 423.50

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Solution

The fourth proportional to 718.20, 991.21 and 423.50 is: 584.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.20 : 991.21 = 423.50 : x
  2. Step 2: Convert to fraction form
    718.20/991.21 = 423.50/x
  3. Step 3: Cross multiply
    718.20x = 991.21 × 423.50
  4. Step 4: Simplify right side
    718.20x = 419,777.44
  5. Step 5: Solve for x
    x = 419,777.44/718.20
  6. Step 6: Final answer
    x = 584.49

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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.