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Finding the Fourth Proportional to 99.09, 137.09 and 86.81

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Solution

The fourth proportional to 99.09, 137.09 and 86.81 is: 120.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.09 : 137.09 = 86.81 : x
  2. Step 2: Convert to fraction form
    99.09/137.09 = 86.81/x
  3. Step 3: Cross multiply
    99.09x = 137.09 × 86.81
  4. Step 4: Simplify right side
    99.09x = 11,900.31
  5. Step 5: Solve for x
    x = 11,900.31/99.09
  6. Step 6: Final answer
    x = 120.10

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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.