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Finding the Fourth Proportional to 724.85, 1,085.43 and 399.86

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Solution

The fourth proportional to 724.85, 1,085.43 and 399.86 is: 598.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.85 : 1,085.43 = 399.86 : x
  2. Step 2: Convert to fraction form
    724.85/1,085.43 = 399.86/x
  3. Step 3: Cross multiply
    724.85x = 1,085.43 × 399.86
  4. Step 4: Simplify right side
    724.85x = 434,020.04
  5. Step 5: Solve for x
    x = 434,020.04/724.85
  6. Step 6: Final answer
    x = 598.77

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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.