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Finding the Fourth Proportional to 379.90, 523.40 and 281.49

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Solution

The fourth proportional to 379.90, 523.40 and 281.49 is: 387.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    379.90 : 523.40 = 281.49 : x
  2. Step 2: Convert to fraction form
    379.90/523.40 = 281.49/x
  3. Step 3: Cross multiply
    379.90x = 523.40 × 281.49
  4. Step 4: Simplify right side
    379.90x = 147,328.50
  5. Step 5: Solve for x
    x = 147,328.50/379.90
  6. Step 6: Final answer
    x = 387.81

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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.