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Finding the Fourth Proportional to 405.12, 559.32 and 280.74

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Solution

The fourth proportional to 405.12, 559.32 and 280.74 is: 387.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.12 : 559.32 = 280.74 : x
  2. Step 2: Convert to fraction form
    405.12/559.32 = 280.74/x
  3. Step 3: Cross multiply
    405.12x = 559.32 × 280.74
  4. Step 4: Simplify right side
    405.12x = 157,020.70
  5. Step 5: Solve for x
    x = 157,020.70/405.12
  6. Step 6: Final answer
    x = 387.59

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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.