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Finding the Fourth Proportional to 84.09, 115.96 and 71.63

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Solution

The fourth proportional to 84.09, 115.96 and 71.63 is: 98.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.09 : 115.96 = 71.63 : x
  2. Step 2: Convert to fraction form
    84.09/115.96 = 71.63/x
  3. Step 3: Cross multiply
    84.09x = 115.96 × 71.63
  4. Step 4: Simplify right side
    84.09x = 8,306.21
  5. Step 5: Solve for x
    x = 8,306.21/84.09
  6. Step 6: Final answer
    x = 98.78

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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.