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Finding the Fourth Proportional to 77.77, 107.47 and 61.53

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Solution

The fourth proportional to 77.77, 107.47 and 61.53 is: 85.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.77 : 107.47 = 61.53 : x
  2. Step 2: Convert to fraction form
    77.77/107.47 = 61.53/x
  3. Step 3: Cross multiply
    77.77x = 107.47 × 61.53
  4. Step 4: Simplify right side
    77.77x = 6,612.09
  5. Step 5: Solve for x
    x = 6,612.09/77.77
  6. Step 6: Final answer
    x = 85.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.