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Finding the Fourth Proportional to 79.74, 119.61 and 71.78

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Solution

The fourth proportional to 79.74, 119.61 and 71.78 is: 107.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.74 : 119.61 = 71.78 : x
  2. Step 2: Convert to fraction form
    79.74/119.61 = 71.78/x
  3. Step 3: Cross multiply
    79.74x = 119.61 × 71.78
  4. Step 4: Simplify right side
    79.74x = 8,585.01
  5. Step 5: Solve for x
    x = 8,585.01/79.74
  6. Step 6: Final answer
    x = 107.66

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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.