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Finding the Fourth Proportional to 390.96, 539.49 and 243.57

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Solution

The fourth proportional to 390.96, 539.49 and 243.57 is: 336.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.96 : 539.49 = 243.57 : x
  2. Step 2: Convert to fraction form
    390.96/539.49 = 243.57/x
  3. Step 3: Cross multiply
    390.96x = 539.49 × 243.57
  4. Step 4: Simplify right side
    390.96x = 131,403.58
  5. Step 5: Solve for x
    x = 131,403.58/390.96
  6. Step 6: Final answer
    x = 336.10

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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.