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Finding the Fourth Proportional to 390.92, 539.50 and 243.57

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Solution

The fourth proportional to 390.92, 539.50 and 243.57 is: 336.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.92 : 539.50 = 243.57 : x
  2. Step 2: Convert to fraction form
    390.92/539.50 = 243.57/x
  3. Step 3: Cross multiply
    390.92x = 539.50 × 243.57
  4. Step 4: Simplify right side
    390.92x = 131,407.54
  5. Step 5: Solve for x
    x = 131,407.54/390.92
  6. Step 6: Final answer
    x = 336.15

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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.