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Finding the Fourth Proportional to 98.09, 146.56 and 80.78

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Solution

The fourth proportional to 98.09, 146.56 and 80.78 is: 120.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.09 : 146.56 = 80.78 : x
  2. Step 2: Convert to fraction form
    98.09/146.56 = 80.78/x
  3. Step 3: Cross multiply
    98.09x = 146.56 × 80.78
  4. Step 4: Simplify right side
    98.09x = 11,837.98
  5. Step 5: Solve for x
    x = 11,837.98/98.09
  6. Step 6: Final answer
    x = 120.68

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.