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Finding the Fourth Proportional to 148.20, 221.95 and 87.31

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Solution

The fourth proportional to 148.20, 221.95 and 87.31 is: 130.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    148.20 : 221.95 = 87.31 : x
  2. Step 2: Convert to fraction form
    148.20/221.95 = 87.31/x
  3. Step 3: Cross multiply
    148.20x = 221.95 × 87.31
  4. Step 4: Simplify right side
    148.20x = 19,378.45
  5. Step 5: Solve for x
    x = 19,378.45/148.20
  6. Step 6: Final answer
    x = 130.76

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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.