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Finding the Fourth Proportional to 724.58, 1,086.87 and 399.80

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Solution

The fourth proportional to 724.58, 1,086.87 and 399.80 is: 599.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.58 : 1,086.87 = 399.80 : x
  2. Step 2: Convert to fraction form
    724.58/1,086.87 = 399.80/x
  3. Step 3: Cross multiply
    724.58x = 1,086.87 × 399.80
  4. Step 4: Simplify right side
    724.58x = 434,530.63
  5. Step 5: Solve for x
    x = 434,530.63/724.58
  6. Step 6: Final answer
    x = 599.70

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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.