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Finding the Fourth Proportional to 378.12, 521.49 and 312.54

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Solution

The fourth proportional to 378.12, 521.49 and 312.54 is: 431.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.12 : 521.49 = 312.54 : x
  2. Step 2: Convert to fraction form
    378.12/521.49 = 312.54/x
  3. Step 3: Cross multiply
    378.12x = 521.49 × 312.54
  4. Step 4: Simplify right side
    378.12x = 162,986.48
  5. Step 5: Solve for x
    x = 162,986.48/378.12
  6. Step 6: Final answer
    x = 431.04

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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.