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Finding the Fourth Proportional to 278.74, 418.21 and 124.78

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Solution

The fourth proportional to 278.74, 418.21 and 124.78 is: 187.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.74 : 418.21 = 124.78 : x
  2. Step 2: Convert to fraction form
    278.74/418.21 = 124.78/x
  3. Step 3: Cross multiply
    278.74x = 418.21 × 124.78
  4. Step 4: Simplify right side
    278.74x = 52,184.24
  5. Step 5: Solve for x
    x = 52,184.24/278.74
  6. Step 6: Final answer
    x = 187.21

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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.