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Finding the Fourth Proportional to 124.23, 186.39 and 85.79

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Solution

The fourth proportional to 124.23, 186.39 and 85.79 is: 128.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.23 : 186.39 = 85.79 : x
  2. Step 2: Convert to fraction form
    124.23/186.39 = 85.79/x
  3. Step 3: Cross multiply
    124.23x = 186.39 × 85.79
  4. Step 4: Simplify right side
    124.23x = 15,990.86
  5. Step 5: Solve for x
    x = 15,990.86/124.23
  6. Step 6: Final answer
    x = 128.72

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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.