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Finding the Fourth Proportional to 123.89, 185.80 and 78.17

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Solution

The fourth proportional to 123.89, 185.80 and 78.17 is: 117.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.89 : 185.80 = 78.17 : x
  2. Step 2: Convert to fraction form
    123.89/185.80 = 78.17/x
  3. Step 3: Cross multiply
    123.89x = 185.80 × 78.17
  4. Step 4: Simplify right side
    123.89x = 14,523.99
  5. Step 5: Solve for x
    x = 14,523.99/123.89
  6. Step 6: Final answer
    x = 117.23

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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.