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Finding the Fourth Proportional to 287.21, 396.31 and 199.91

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Solution

The fourth proportional to 287.21, 396.31 and 199.91 is: 275.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.21 : 396.31 = 199.91 : x
  2. Step 2: Convert to fraction form
    287.21/396.31 = 199.91/x
  3. Step 3: Cross multiply
    287.21x = 396.31 × 199.91
  4. Step 4: Simplify right side
    287.21x = 79,226.33
  5. Step 5: Solve for x
    x = 79,226.33/287.21
  6. Step 6: Final answer
    x = 275.85

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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.