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Finding the Fourth Proportional to 378.74, 522.01 and 312.55

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Solution

The fourth proportional to 378.74, 522.01 and 312.55 is: 430.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.74 : 522.01 = 312.55 : x
  2. Step 2: Convert to fraction form
    378.74/522.01 = 312.55/x
  3. Step 3: Cross multiply
    378.74x = 522.01 × 312.55
  4. Step 4: Simplify right side
    378.74x = 163,154.23
  5. Step 5: Solve for x
    x = 163,154.23/378.74
  6. Step 6: Final answer
    x = 430.78

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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.