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Finding the Fourth Proportional to 391.54, 540.30 and 216.88

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Solution

The fourth proportional to 391.54, 540.30 and 216.88 is: 299.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.54 : 540.30 = 216.88 : x
  2. Step 2: Convert to fraction form
    391.54/540.30 = 216.88/x
  3. Step 3: Cross multiply
    391.54x = 540.30 × 216.88
  4. Step 4: Simplify right side
    391.54x = 117,180.26
  5. Step 5: Solve for x
    x = 117,180.26/391.54
  6. Step 6: Final answer
    x = 299.28

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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.