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Finding the Fourth Proportional to 391.69, 540.11 and 387.74

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Solution

The fourth proportional to 391.69, 540.11 and 387.74 is: 534.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.69 : 540.11 = 387.74 : x
  2. Step 2: Convert to fraction form
    391.69/540.11 = 387.74/x
  3. Step 3: Cross multiply
    391.69x = 540.11 × 387.74
  4. Step 4: Simplify right side
    391.69x = 209,420.31
  5. Step 5: Solve for x
    x = 209,420.31/391.69
  6. Step 6: Final answer
    x = 534.66

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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.