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Finding the Fourth Proportional to 724.29, 1,085.62 and 312.81

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Solution

The fourth proportional to 724.29, 1,085.62 and 312.81 is: 468.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.29 : 1,085.62 = 312.81 : x
  2. Step 2: Convert to fraction form
    724.29/1,085.62 = 312.81/x
  3. Step 3: Cross multiply
    724.29x = 1,085.62 × 312.81
  4. Step 4: Simplify right side
    724.29x = 339,588.53
  5. Step 5: Solve for x
    x = 339,588.53/724.29
  6. Step 6: Final answer
    x = 468.86

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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.