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Finding the Fourth Proportional to 77.76, 107.28 and 48.60

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Solution

The fourth proportional to 77.76, 107.28 and 48.60 is: 67.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.76 : 107.28 = 48.60 : x
  2. Step 2: Convert to fraction form
    77.76/107.28 = 48.60/x
  3. Step 3: Cross multiply
    77.76x = 107.28 × 48.60
  4. Step 4: Simplify right side
    77.76x = 5,213.81
  5. Step 5: Solve for x
    x = 5,213.81/77.76
  6. Step 6: Final answer
    x = 67.05

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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.