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Finding the Fourth Proportional to 309.31, 426.40 and 191.21

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Solution

The fourth proportional to 309.31, 426.40 and 191.21 is: 263.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.31 : 426.40 = 191.21 : x
  2. Step 2: Convert to fraction form
    309.31/426.40 = 191.21/x
  3. Step 3: Cross multiply
    309.31x = 426.40 × 191.21
  4. Step 4: Simplify right side
    309.31x = 81,532.54
  5. Step 5: Solve for x
    x = 81,532.54/309.31
  6. Step 6: Final answer
    x = 263.60

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.