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Finding the Fourth Proportional to 318.54, 478.20 and 242.40

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Solution

The fourth proportional to 318.54, 478.20 and 242.40 is: 363.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.54 : 478.20 = 242.40 : x
  2. Step 2: Convert to fraction form
    318.54/478.20 = 242.40/x
  3. Step 3: Cross multiply
    318.54x = 478.20 × 242.40
  4. Step 4: Simplify right side
    318.54x = 115,915.68
  5. Step 5: Solve for x
    x = 115,915.68/318.54
  6. Step 6: Final answer
    x = 363.90

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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.