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Finding the Fourth Proportional to 105.80, 158.16 and 81.50

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Solution

The fourth proportional to 105.80, 158.16 and 81.50 is: 121.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.80 : 158.16 = 81.50 : x
  2. Step 2: Convert to fraction form
    105.80/158.16 = 81.50/x
  3. Step 3: Cross multiply
    105.80x = 158.16 × 81.50
  4. Step 4: Simplify right side
    105.80x = 12,889.63
  5. Step 5: Solve for x
    x = 12,889.63/105.80
  6. Step 6: Final answer
    x = 121.83

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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.