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Finding the Fourth Proportional to 77.49, 107.12 and 74.28

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Solution

The fourth proportional to 77.49, 107.12 and 74.28 is: 102.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.49 : 107.12 = 74.28 : x
  2. Step 2: Convert to fraction form
    77.49/107.12 = 74.28/x
  3. Step 3: Cross multiply
    77.49x = 107.12 × 74.28
  4. Step 4: Simplify right side
    77.49x = 7,957.46
  5. Step 5: Solve for x
    x = 7,957.46/77.49
  6. Step 6: Final answer
    x = 102.69

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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.