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Finding the Fourth Proportional to 187.90, 281.31 and 142.10

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Solution

The fourth proportional to 187.90, 281.31 and 142.10 is: 212.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.90 : 281.31 = 142.10 : x
  2. Step 2: Convert to fraction form
    187.90/281.31 = 142.10/x
  3. Step 3: Cross multiply
    187.90x = 281.31 × 142.10
  4. Step 4: Simplify right side
    187.90x = 39,974.15
  5. Step 5: Solve for x
    x = 39,974.15/187.90
  6. Step 6: Final answer
    x = 212.75

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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.