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Finding the Fourth Proportional to 391.51, 540.31 and 225.75

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Solution

The fourth proportional to 391.51, 540.31 and 225.75 is: 311.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.51 : 540.31 = 225.75 : x
  2. Step 2: Convert to fraction form
    391.51/540.31 = 225.75/x
  3. Step 3: Cross multiply
    391.51x = 540.31 × 225.75
  4. Step 4: Simplify right side
    391.51x = 121,974.98
  5. Step 5: Solve for x
    x = 121,974.98/391.51
  6. Step 6: Final answer
    x = 311.55

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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.