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Finding the Fourth Proportional to 281.18, 420.90 and 212.96

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Solution

The fourth proportional to 281.18, 420.90 and 212.96 is: 318.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.18 : 420.90 = 212.96 : x
  2. Step 2: Convert to fraction form
    281.18/420.90 = 212.96/x
  3. Step 3: Cross multiply
    281.18x = 420.90 × 212.96
  4. Step 4: Simplify right side
    281.18x = 89,634.86
  5. Step 5: Solve for x
    x = 89,634.86/281.18
  6. Step 6: Final answer
    x = 318.78

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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.