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Finding the Fourth Proportional to 378.09, 521.70 and 212.28

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Solution

The fourth proportional to 378.09, 521.70 and 212.28 is: 292.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.09 : 521.70 = 212.28 : x
  2. Step 2: Convert to fraction form
    378.09/521.70 = 212.28/x
  3. Step 3: Cross multiply
    378.09x = 521.70 × 212.28
  4. Step 4: Simplify right side
    378.09x = 110,746.48
  5. Step 5: Solve for x
    x = 110,746.48/378.09
  6. Step 6: Final answer
    x = 292.91

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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.