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Finding the Fourth Proportional to 421.29, 581.49 and 281.43

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Solution

The fourth proportional to 421.29, 581.49 and 281.43 is: 388.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.29 : 581.49 = 281.43 : x
  2. Step 2: Convert to fraction form
    421.29/581.49 = 281.43/x
  3. Step 3: Cross multiply
    421.29x = 581.49 × 281.43
  4. Step 4: Simplify right side
    421.29x = 163,648.73
  5. Step 5: Solve for x
    x = 163,648.73/421.29
  6. Step 6: Final answer
    x = 388.45

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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.