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Finding the Fourth Proportional to 378.78, 522.84 and 313.20

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Solution

The fourth proportional to 378.78, 522.84 and 313.20 is: 432.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.78 : 522.84 = 313.20 : x
  2. Step 2: Convert to fraction form
    378.78/522.84 = 313.20/x
  3. Step 3: Cross multiply
    378.78x = 522.84 × 313.20
  4. Step 4: Simplify right side
    378.78x = 163,753.49
  5. Step 5: Solve for x
    x = 163,753.49/378.78
  6. Step 6: Final answer
    x = 432.32

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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.