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Finding the Fourth Proportional to 390.60, 539.04 and 243.20

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Solution

The fourth proportional to 390.60, 539.04 and 243.20 is: 335.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.60 : 539.04 = 243.20 : x
  2. Step 2: Convert to fraction form
    390.60/539.04 = 243.20/x
  3. Step 3: Cross multiply
    390.60x = 539.04 × 243.20
  4. Step 4: Simplify right side
    390.60x = 131,094.53
  5. Step 5: Solve for x
    x = 131,094.53/390.60
  6. Step 6: Final answer
    x = 335.62

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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.