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Finding the Fourth Proportional to 77.28, 115.09 and 72.63

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Solution

The fourth proportional to 77.28, 115.09 and 72.63 is: 108.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.28 : 115.09 = 72.63 : x
  2. Step 2: Convert to fraction form
    77.28/115.09 = 72.63/x
  3. Step 3: Cross multiply
    77.28x = 115.09 × 72.63
  4. Step 4: Simplify right side
    77.28x = 8,358.99
  5. Step 5: Solve for x
    x = 8,358.99/77.28
  6. Step 6: Final answer
    x = 108.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.