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Finding the Fourth Proportional to 77.91, 117.56 and 71.25

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Solution

The fourth proportional to 77.91, 117.56 and 71.25 is: 107.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.91 : 117.56 = 71.25 : x
  2. Step 2: Convert to fraction form
    77.91/117.56 = 71.25/x
  3. Step 3: Cross multiply
    77.91x = 117.56 × 71.25
  4. Step 4: Simplify right side
    77.91x = 8,375.79
  5. Step 5: Solve for x
    x = 8,375.79/77.91
  6. Step 6: Final answer
    x = 107.51

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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.