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Finding the Fourth Proportional to 82.16, 113.22 and 77.90

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Solution

The fourth proportional to 82.16, 113.22 and 77.90 is: 107.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.16 : 113.22 = 77.90 : x
  2. Step 2: Convert to fraction form
    82.16/113.22 = 77.90/x
  3. Step 3: Cross multiply
    82.16x = 113.22 × 77.90
  4. Step 4: Simplify right side
    82.16x = 8,819.84
  5. Step 5: Solve for x
    x = 8,819.84/82.16
  6. Step 6: Final answer
    x = 107.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.