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Finding the Fourth Proportional to 79.72, 119.67 and 77.65

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Solution

The fourth proportional to 79.72, 119.67 and 77.65 is: 116.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.72 : 119.67 = 77.65 : x
  2. Step 2: Convert to fraction form
    79.72/119.67 = 77.65/x
  3. Step 3: Cross multiply
    79.72x = 119.67 × 77.65
  4. Step 4: Simplify right side
    79.72x = 9,291.79
  5. Step 5: Solve for x
    x = 9,291.79/79.72
  6. Step 6: Final answer
    x = 116.56

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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.