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Finding the Fourth Proportional to 281.20, 387.84 and 211.28

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Solution

The fourth proportional to 281.20, 387.84 and 211.28 is: 291.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.20 : 387.84 = 211.28 : x
  2. Step 2: Convert to fraction form
    281.20/387.84 = 211.28/x
  3. Step 3: Cross multiply
    281.20x = 387.84 × 211.28
  4. Step 4: Simplify right side
    281.20x = 81,942.84
  5. Step 5: Solve for x
    x = 81,942.84/281.20
  6. Step 6: Final answer
    x = 291.40

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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.