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Finding the Fourth Proportional to 931.38, 1,285.09 and 538.39

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Solution

The fourth proportional to 931.38, 1,285.09 and 538.39 is: 742.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    931.38 : 1,285.09 = 538.39 : x
  2. Step 2: Convert to fraction form
    931.38/1,285.09 = 538.39/x
  3. Step 3: Cross multiply
    931.38x = 1,285.09 × 538.39
  4. Step 4: Simplify right side
    931.38x = 691,879.61
  5. Step 5: Solve for x
    x = 691,879.61/931.38
  6. Step 6: Final answer
    x = 742.85

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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.