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Finding the Fourth Proportional to 77.68, 107.21 and 49.30

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Solution

The fourth proportional to 77.68, 107.21 and 49.30 is: 68.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.68 : 107.21 = 49.30 : x
  2. Step 2: Convert to fraction form
    77.68/107.21 = 49.30/x
  3. Step 3: Cross multiply
    77.68x = 107.21 × 49.30
  4. Step 4: Simplify right side
    77.68x = 5,285.45
  5. Step 5: Solve for x
    x = 5,285.45/77.68
  6. Step 6: Final answer
    x = 68.04

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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.