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Finding the Fourth Proportional to 79.74, 118.86 and 77.70

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Solution

The fourth proportional to 79.74, 118.86 and 77.70 is: 115.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.74 : 118.86 = 77.70 : x
  2. Step 2: Convert to fraction form
    79.74/118.86 = 77.70/x
  3. Step 3: Cross multiply
    79.74x = 118.86 × 77.70
  4. Step 4: Simplify right side
    79.74x = 9,235.42
  5. Step 5: Solve for x
    x = 9,235.42/79.74
  6. Step 6: Final answer
    x = 115.82

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.