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Finding the Fourth Proportional to 86.52, 129.80 and 43.80

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Solution

The fourth proportional to 86.52, 129.80 and 43.80 is: 65.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.52 : 129.80 = 43.80 : x
  2. Step 2: Convert to fraction form
    86.52/129.80 = 43.80/x
  3. Step 3: Cross multiply
    86.52x = 129.80 × 43.80
  4. Step 4: Simplify right side
    86.52x = 5,685.24
  5. Step 5: Solve for x
    x = 5,685.24/86.52
  6. Step 6: Final answer
    x = 65.71

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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.