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Finding the Fourth Proportional to 387.85, 535.21 and 213.19

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Solution

The fourth proportional to 387.85, 535.21 and 213.19 is: 294.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.85 : 535.21 = 213.19 : x
  2. Step 2: Convert to fraction form
    387.85/535.21 = 213.19/x
  3. Step 3: Cross multiply
    387.85x = 535.21 × 213.19
  4. Step 4: Simplify right side
    387.85x = 114,101.42
  5. Step 5: Solve for x
    x = 114,101.42/387.85
  6. Step 6: Final answer
    x = 294.19

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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.