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Finding the Fourth Proportional to 98.13, 135.09 and 85.20

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Solution

The fourth proportional to 98.13, 135.09 and 85.20 is: 117.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.13 : 135.09 = 85.20 : x
  2. Step 2: Convert to fraction form
    98.13/135.09 = 85.20/x
  3. Step 3: Cross multiply
    98.13x = 135.09 × 85.20
  4. Step 4: Simplify right side
    98.13x = 11,509.67
  5. Step 5: Solve for x
    x = 11,509.67/98.13
  6. Step 6: Final answer
    x = 117.29

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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.