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Finding the Fourth Proportional to 398.55, 550.50 and 287.85

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Solution

The fourth proportional to 398.55, 550.50 and 287.85 is: 397.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.55 : 550.50 = 287.85 : x
  2. Step 2: Convert to fraction form
    398.55/550.50 = 287.85/x
  3. Step 3: Cross multiply
    398.55x = 550.50 × 287.85
  4. Step 4: Simplify right side
    398.55x = 158,462.41
  5. Step 5: Solve for x
    x = 158,462.41/398.55
  6. Step 6: Final answer
    x = 397.59

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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.