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Finding the Fourth Proportional to 99.80, 137.91 and 89.96

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Solution

The fourth proportional to 99.80, 137.91 and 89.96 is: 124.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.80 : 137.91 = 89.96 : x
  2. Step 2: Convert to fraction form
    99.80/137.91 = 89.96/x
  3. Step 3: Cross multiply
    99.80x = 137.91 × 89.96
  4. Step 4: Simplify right side
    99.80x = 12,406.38
  5. Step 5: Solve for x
    x = 12,406.38/99.80
  6. Step 6: Final answer
    x = 124.31

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.