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Finding the Fourth Proportional to 98.06, 135.42 and 78.80

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Solution

The fourth proportional to 98.06, 135.42 and 78.80 is: 108.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.06 : 135.42 = 78.80 : x
  2. Step 2: Convert to fraction form
    98.06/135.42 = 78.80/x
  3. Step 3: Cross multiply
    98.06x = 135.42 × 78.80
  4. Step 4: Simplify right side
    98.06x = 10,671.10
  5. Step 5: Solve for x
    x = 10,671.10/98.06
  6. Step 6: Final answer
    x = 108.82

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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.