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Finding the Fourth Proportional to 391.57, 540.36 and 216.91

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Solution

The fourth proportional to 391.57, 540.36 and 216.91 is: 299.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.57 : 540.36 = 216.91 : x
  2. Step 2: Convert to fraction form
    391.57/540.36 = 216.91/x
  3. Step 3: Cross multiply
    391.57x = 540.36 × 216.91
  4. Step 4: Simplify right side
    391.57x = 117,211.65
  5. Step 5: Solve for x
    x = 117,211.65/391.57
  6. Step 6: Final answer
    x = 299.34

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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.