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Finding the Fourth Proportional to 77.58, 106.79 and 66.65

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Solution

The fourth proportional to 77.58, 106.79 and 66.65 is: 91.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.58 : 106.79 = 66.65 : x
  2. Step 2: Convert to fraction form
    77.58/106.79 = 66.65/x
  3. Step 3: Cross multiply
    77.58x = 106.79 × 66.65
  4. Step 4: Simplify right side
    77.58x = 7,116.69
  5. Step 5: Solve for x
    x = 7,116.69/77.58
  6. Step 6: Final answer
    x = 91.73

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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.