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Finding the Fourth Proportional to 124.20, 186.28 and 76.40

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Solution

The fourth proportional to 124.20, 186.28 and 76.40 is: 114.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.20 : 186.28 = 76.40 : x
  2. Step 2: Convert to fraction form
    124.20/186.28 = 76.40/x
  3. Step 3: Cross multiply
    124.20x = 186.28 × 76.40
  4. Step 4: Simplify right side
    124.20x = 14,231.79
  5. Step 5: Solve for x
    x = 14,231.79/124.20
  6. Step 6: Final answer
    x = 114.59

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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.