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Finding the Fourth Proportional to 98.31, 135.74 and 72.09

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Solution

The fourth proportional to 98.31, 135.74 and 72.09 is: 99.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.31 : 135.74 = 72.09 : x
  2. Step 2: Convert to fraction form
    98.31/135.74 = 72.09/x
  3. Step 3: Cross multiply
    98.31x = 135.74 × 72.09
  4. Step 4: Simplify right side
    98.31x = 9,785.68
  5. Step 5: Solve for x
    x = 9,785.68/98.31
  6. Step 6: Final answer
    x = 99.54

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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.