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Finding the Fourth Proportional to 326.80, 489.91 and 211.31

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Solution

The fourth proportional to 326.80, 489.91 and 211.31 is: 316.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    326.80 : 489.91 = 211.31 : x
  2. Step 2: Convert to fraction form
    326.80/489.91 = 211.31/x
  3. Step 3: Cross multiply
    326.80x = 489.91 × 211.31
  4. Step 4: Simplify right side
    326.80x = 103,522.88
  5. Step 5: Solve for x
    x = 103,522.88/326.80
  6. Step 6: Final answer
    x = 316.78

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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.