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Finding the Fourth Proportional to 122.49, 183.72 and 76.80

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Solution

The fourth proportional to 122.49, 183.72 and 76.80 is: 115.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.49 : 183.72 = 76.80 : x
  2. Step 2: Convert to fraction form
    122.49/183.72 = 76.80/x
  3. Step 3: Cross multiply
    122.49x = 183.72 × 76.80
  4. Step 4: Simplify right side
    122.49x = 14,109.70
  5. Step 5: Solve for x
    x = 14,109.70/122.49
  6. Step 6: Final answer
    x = 115.19

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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.