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Finding the Fourth Proportional to 99.80, 149.70 and 87.92

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Solution

The fourth proportional to 99.80, 149.70 and 87.92 is: 131.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.80 : 149.70 = 87.92 : x
  2. Step 2: Convert to fraction form
    99.80/149.70 = 87.92/x
  3. Step 3: Cross multiply
    99.80x = 149.70 × 87.92
  4. Step 4: Simplify right side
    99.80x = 13,161.62
  5. Step 5: Solve for x
    x = 13,161.62/99.80
  6. Step 6: Final answer
    x = 131.88

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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.