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Finding the Fourth Proportional to 77.68, 107.20 and 62.16

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Solution

The fourth proportional to 77.68, 107.20 and 62.16 is: 85.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.68 : 107.20 = 62.16 : x
  2. Step 2: Convert to fraction form
    77.68/107.20 = 62.16/x
  3. Step 3: Cross multiply
    77.68x = 107.20 × 62.16
  4. Step 4: Simplify right side
    77.68x = 6,663.55
  5. Step 5: Solve for x
    x = 6,663.55/77.68
  6. Step 6: Final answer
    x = 85.78

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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.