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Finding the Fourth Proportional to 318.79, 478.72 and 278.56

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Solution

The fourth proportional to 318.79, 478.72 and 278.56 is: 418.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.79 : 478.72 = 278.56 : x
  2. Step 2: Convert to fraction form
    318.79/478.72 = 278.56/x
  3. Step 3: Cross multiply
    318.79x = 478.72 × 278.56
  4. Step 4: Simplify right side
    318.79x = 133,352.24
  5. Step 5: Solve for x
    x = 133,352.24/318.79
  6. Step 6: Final answer
    x = 418.31

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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.