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Finding the Fourth Proportional to 51.24, 76.78 and 39.87

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Solution

The fourth proportional to 51.24, 76.78 and 39.87 is: 59.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.24 : 76.78 = 39.87 : x
  2. Step 2: Convert to fraction form
    51.24/76.78 = 39.87/x
  3. Step 3: Cross multiply
    51.24x = 76.78 × 39.87
  4. Step 4: Simplify right side
    51.24x = 3,061.22
  5. Step 5: Solve for x
    x = 3,061.22/51.24
  6. Step 6: Final answer
    x = 59.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.