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Finding the Fourth Proportional to 115.85, 159.88 and 82.21

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Solution

The fourth proportional to 115.85, 159.88 and 82.21 is: 113.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    115.85 : 159.88 = 82.21 : x
  2. Step 2: Convert to fraction form
    115.85/159.88 = 82.21/x
  3. Step 3: Cross multiply
    115.85x = 159.88 × 82.21
  4. Step 4: Simplify right side
    115.85x = 13,143.73
  5. Step 5: Solve for x
    x = 13,143.73/115.85
  6. Step 6: Final answer
    x = 113.45

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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.