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Finding the Fourth Proportional to 378.78, 522.60 and 231.31

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Solution

The fourth proportional to 378.78, 522.60 and 231.31 is: 319.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.78 : 522.60 = 231.31 : x
  2. Step 2: Convert to fraction form
    378.78/522.60 = 231.31/x
  3. Step 3: Cross multiply
    378.78x = 522.60 × 231.31
  4. Step 4: Simplify right side
    378.78x = 120,880.75
  5. Step 5: Solve for x
    x = 120,880.75/378.78
  6. Step 6: Final answer
    x = 319.13

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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.