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Finding the Fourth Proportional to 391.49, 540.23 and 216.84

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Solution

The fourth proportional to 391.49, 540.23 and 216.84 is: 299.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.49 : 540.23 = 216.84 : x
  2. Step 2: Convert to fraction form
    391.49/540.23 = 216.84/x
  3. Step 3: Cross multiply
    391.49x = 540.23 × 216.84
  4. Step 4: Simplify right side
    391.49x = 117,143.47
  5. Step 5: Solve for x
    x = 117,143.47/391.49
  6. Step 6: Final answer
    x = 299.22

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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.