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Finding the Fourth Proportional to 378.80, 522.70 and 213

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Solution

The fourth proportional to 378.80, 522.70 and 213 is: 293.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.80 : 522.70 = 213 : x
  2. Step 2: Convert to fraction form
    378.80/522.70 = 213/x
  3. Step 3: Cross multiply
    378.80x = 522.70 × 213
  4. Step 4: Simplify right side
    378.80x = 111,335.10
  5. Step 5: Solve for x
    x = 111,335.10/378.80
  6. Step 6: Final answer
    x = 293.92

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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.