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Finding the Fourth Proportional to 281.21, 387.87 and 211.52

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Solution

The fourth proportional to 281.21, 387.87 and 211.52 is: 291.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.21 : 387.87 = 211.52 : x
  2. Step 2: Convert to fraction form
    281.21/387.87 = 211.52/x
  3. Step 3: Cross multiply
    281.21x = 387.87 × 211.52
  4. Step 4: Simplify right side
    281.21x = 82,042.26
  5. Step 5: Solve for x
    x = 82,042.26/281.21
  6. Step 6: Final answer
    x = 291.75

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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.