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Finding the Fourth Proportional to 311.80, 467.75 and 138.47

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Solution

The fourth proportional to 311.80, 467.75 and 138.47 is: 207.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.80 : 467.75 = 138.47 : x
  2. Step 2: Convert to fraction form
    311.80/467.75 = 138.47/x
  3. Step 3: Cross multiply
    311.80x = 467.75 × 138.47
  4. Step 4: Simplify right side
    311.80x = 64,766.57
  5. Step 5: Solve for x
    x = 64,766.57/311.80
  6. Step 6: Final answer
    x = 207.72

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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.