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Finding the Fourth Proportional to 78.79, 118.09 and 69.79

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Solution

The fourth proportional to 78.79, 118.09 and 69.79 is: 104.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.79 : 118.09 = 69.79 : x
  2. Step 2: Convert to fraction form
    78.79/118.09 = 69.79/x
  3. Step 3: Cross multiply
    78.79x = 118.09 × 69.79
  4. Step 4: Simplify right side
    78.79x = 8,240.56
  5. Step 5: Solve for x
    x = 8,240.56/78.79
  6. Step 6: Final answer
    x = 104.60

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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.