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Finding the Fourth Proportional to 98.11, 135.30 and 87.31

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Solution

The fourth proportional to 98.11, 135.30 and 87.31 is: 120.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.11 : 135.30 = 87.31 : x
  2. Step 2: Convert to fraction form
    98.11/135.30 = 87.31/x
  3. Step 3: Cross multiply
    98.11x = 135.30 × 87.31
  4. Step 4: Simplify right side
    98.11x = 11,813.04
  5. Step 5: Solve for x
    x = 11,813.04/98.11
  6. Step 6: Final answer
    x = 120.41

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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.