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Finding the Fourth Proportional to 391.65, 540.09 and 251.75

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Solution

The fourth proportional to 391.65, 540.09 and 251.75 is: 347.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.65 : 540.09 = 251.75 : x
  2. Step 2: Convert to fraction form
    391.65/540.09 = 251.75/x
  3. Step 3: Cross multiply
    391.65x = 540.09 × 251.75
  4. Step 4: Simplify right side
    391.65x = 135,967.66
  5. Step 5: Solve for x
    x = 135,967.66/391.65
  6. Step 6: Final answer
    x = 347.17

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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.