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Finding the Fourth Proportional to 80.65, 121.00 and 51.81

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Solution

The fourth proportional to 80.65, 121.00 and 51.81 is: 77.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.65 : 121.00 = 51.81 : x
  2. Step 2: Convert to fraction form
    80.65/121.00 = 51.81/x
  3. Step 3: Cross multiply
    80.65x = 121.00 × 51.81
  4. Step 4: Simplify right side
    80.65x = 6,269.23
  5. Step 5: Solve for x
    x = 6,269.23/80.65
  6. Step 6: Final answer
    x = 77.74

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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.