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Finding the Fourth Proportional to 391.65, 540.36 and 308.63

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Solution

The fourth proportional to 391.65, 540.36 and 308.63 is: 425.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.65 : 540.36 = 308.63 : x
  2. Step 2: Convert to fraction form
    391.65/540.36 = 308.63/x
  3. Step 3: Cross multiply
    391.65x = 540.36 × 308.63
  4. Step 4: Simplify right side
    391.65x = 166,768.61
  5. Step 5: Solve for x
    x = 166,768.61/391.65
  6. Step 6: Final answer
    x = 425.81

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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.