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Finding the Fourth Proportional to 78.79, 108.07 and 77.47

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Solution

The fourth proportional to 78.79, 108.07 and 77.47 is: 106.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.79 : 108.07 = 77.47 : x
  2. Step 2: Convert to fraction form
    78.79/108.07 = 77.47/x
  3. Step 3: Cross multiply
    78.79x = 108.07 × 77.47
  4. Step 4: Simplify right side
    78.79x = 8,372.18
  5. Step 5: Solve for x
    x = 8,372.18/78.79
  6. Step 6: Final answer
    x = 106.26

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.