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Finding the Fourth Proportional to 213.13, 319.66 and 66.85

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Solution

The fourth proportional to 213.13, 319.66 and 66.85 is: 100.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.13 : 319.66 = 66.85 : x
  2. Step 2: Convert to fraction form
    213.13/319.66 = 66.85/x
  3. Step 3: Cross multiply
    213.13x = 319.66 × 66.85
  4. Step 4: Simplify right side
    213.13x = 21,367.67
  5. Step 5: Solve for x
    x = 21,367.67/213.13
  6. Step 6: Final answer
    x = 100.26

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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.