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Finding the Fourth Proportional to 309.21, 426.62 and 191.20

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Solution

The fourth proportional to 309.21, 426.62 and 191.20 is: 263.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.21 : 426.62 = 191.20 : x
  2. Step 2: Convert to fraction form
    309.21/426.62 = 191.20/x
  3. Step 3: Cross multiply
    309.21x = 426.62 × 191.20
  4. Step 4: Simplify right side
    309.21x = 81,569.74
  5. Step 5: Solve for x
    x = 81,569.74/309.21
  6. Step 6: Final answer
    x = 263.80

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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.