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Finding the Fourth Proportional to 123.78, 185.53 and 69.71

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Solution

The fourth proportional to 123.78, 185.53 and 69.71 is: 104.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.78 : 185.53 = 69.71 : x
  2. Step 2: Convert to fraction form
    123.78/185.53 = 69.71/x
  3. Step 3: Cross multiply
    123.78x = 185.53 × 69.71
  4. Step 4: Simplify right side
    123.78x = 12,933.30
  5. Step 5: Solve for x
    x = 12,933.30/123.78
  6. Step 6: Final answer
    x = 104.49

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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.