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Finding the Fourth Proportional to 281.78, 422.67 and 86.78

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Solution

The fourth proportional to 281.78, 422.67 and 86.78 is: 130.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.78 : 422.67 = 86.78 : x
  2. Step 2: Convert to fraction form
    281.78/422.67 = 86.78/x
  3. Step 3: Cross multiply
    281.78x = 422.67 × 86.78
  4. Step 4: Simplify right side
    281.78x = 36,679.30
  5. Step 5: Solve for x
    x = 36,679.30/281.78
  6. Step 6: Final answer
    x = 130.17

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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.