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Finding the Fourth Proportional to 378.19, 521.89 and 212.40

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Solution

The fourth proportional to 378.19, 521.89 and 212.40 is: 293.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.19 : 521.89 = 212.40 : x
  2. Step 2: Convert to fraction form
    378.19/521.89 = 212.40/x
  3. Step 3: Cross multiply
    378.19x = 521.89 × 212.40
  4. Step 4: Simplify right side
    378.19x = 110,849.44
  5. Step 5: Solve for x
    x = 110,849.44/378.19
  6. Step 6: Final answer
    x = 293.11

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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.