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Finding the Fourth Proportional to 140.81, 210.80 and 79.85

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Solution

The fourth proportional to 140.81, 210.80 and 79.85 is: 119.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.81 : 210.80 = 79.85 : x
  2. Step 2: Convert to fraction form
    140.81/210.80 = 79.85/x
  3. Step 3: Cross multiply
    140.81x = 210.80 × 79.85
  4. Step 4: Simplify right side
    140.81x = 16,833.11
  5. Step 5: Solve for x
    x = 16,833.11/140.81
  6. Step 6: Final answer
    x = 119.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.