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Finding the Fourth Proportional to 84.15, 115.88 and 71.82

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Solution

The fourth proportional to 84.15, 115.88 and 71.82 is: 98.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.15 : 115.88 = 71.82 : x
  2. Step 2: Convert to fraction form
    84.15/115.88 = 71.82/x
  3. Step 3: Cross multiply
    84.15x = 115.88 × 71.82
  4. Step 4: Simplify right side
    84.15x = 8,322.14
  5. Step 5: Solve for x
    x = 8,322.14/84.15
  6. Step 6: Final answer
    x = 98.90

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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.