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Finding the Fourth Proportional to 77.40, 116.09 and 40.85

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Solution

The fourth proportional to 77.40, 116.09 and 40.85 is: 61.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.40 : 116.09 = 40.85 : x
  2. Step 2: Convert to fraction form
    77.40/116.09 = 40.85/x
  3. Step 3: Cross multiply
    77.40x = 116.09 × 40.85
  4. Step 4: Simplify right side
    77.40x = 4,741.49
  5. Step 5: Solve for x
    x = 4,741.49/77.40
  6. Step 6: Final answer
    x = 61.26

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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.