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Finding the Fourth Proportional to 212.91, 319.90 and 135.91

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Solution

The fourth proportional to 212.91, 319.90 and 135.91 is: 204.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.91 : 319.90 = 135.91 : x
  2. Step 2: Convert to fraction form
    212.91/319.90 = 135.91/x
  3. Step 3: Cross multiply
    212.91x = 319.90 × 135.91
  4. Step 4: Simplify right side
    212.91x = 43,477.61
  5. Step 5: Solve for x
    x = 43,477.61/212.91
  6. Step 6: Final answer
    x = 204.21

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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.