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Finding the Fourth Proportional to 123.90, 185.69 and 87.75

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Solution

The fourth proportional to 123.90, 185.69 and 87.75 is: 131.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.90 : 185.69 = 87.75 : x
  2. Step 2: Convert to fraction form
    123.90/185.69 = 87.75/x
  3. Step 3: Cross multiply
    123.90x = 185.69 × 87.75
  4. Step 4: Simplify right side
    123.90x = 16,294.52
  5. Step 5: Solve for x
    x = 16,294.52/123.90
  6. Step 6: Final answer
    x = 131.52

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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.