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Finding the Fourth Proportional to 378.12, 521.28 and 253.56

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Solution

The fourth proportional to 378.12, 521.28 and 253.56 is: 349.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.12 : 521.28 = 253.56 : x
  2. Step 2: Convert to fraction form
    378.12/521.28 = 253.56/x
  3. Step 3: Cross multiply
    378.12x = 521.28 × 253.56
  4. Step 4: Simplify right side
    378.12x = 132,175.76
  5. Step 5: Solve for x
    x = 132,175.76/378.12
  6. Step 6: Final answer
    x = 349.56

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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.