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Finding the Fourth Proportional to 77.24, 115.29 and 69.12

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Solution

The fourth proportional to 77.24, 115.29 and 69.12 is: 103.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.24 : 115.29 = 69.12 : x
  2. Step 2: Convert to fraction form
    77.24/115.29 = 69.12/x
  3. Step 3: Cross multiply
    77.24x = 115.29 × 69.12
  4. Step 4: Simplify right side
    77.24x = 7,968.84
  5. Step 5: Solve for x
    x = 7,968.84/77.24
  6. Step 6: Final answer
    x = 103.17

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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.