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Finding the Fourth Proportional to 405.49, 559.28 and 281.15

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Solution

The fourth proportional to 405.49, 559.28 and 281.15 is: 387.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.49 : 559.28 = 281.15 : x
  2. Step 2: Convert to fraction form
    405.49/559.28 = 281.15/x
  3. Step 3: Cross multiply
    405.49x = 559.28 × 281.15
  4. Step 4: Simplify right side
    405.49x = 157,240.17
  5. Step 5: Solve for x
    x = 157,240.17/405.49
  6. Step 6: Final answer
    x = 387.78

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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.