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Finding the Fourth Proportional to 83.64, 126.09 and 78.07

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Solution

The fourth proportional to 83.64, 126.09 and 78.07 is: 117.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.64 : 126.09 = 78.07 : x
  2. Step 2: Convert to fraction form
    83.64/126.09 = 78.07/x
  3. Step 3: Cross multiply
    83.64x = 126.09 × 78.07
  4. Step 4: Simplify right side
    83.64x = 9,843.53
  5. Step 5: Solve for x
    x = 9,843.53/83.64
  6. Step 6: Final answer
    x = 117.68

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.