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Finding the Fourth Proportional to 77.90, 117.12 and 69.02

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Solution

The fourth proportional to 77.90, 117.12 and 69.02 is: 103.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.90 : 117.12 = 69.02 : x
  2. Step 2: Convert to fraction form
    77.90/117.12 = 69.02/x
  3. Step 3: Cross multiply
    77.90x = 117.12 × 69.02
  4. Step 4: Simplify right side
    77.90x = 8,083.62
  5. Step 5: Solve for x
    x = 8,083.62/77.90
  6. Step 6: Final answer
    x = 103.77

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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.