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Finding the Fourth Proportional to 405.51, 559.90 and 280.96

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Solution

The fourth proportional to 405.51, 559.90 and 280.96 is: 387.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.51 : 559.90 = 280.96 : x
  2. Step 2: Convert to fraction form
    405.51/559.90 = 280.96/x
  3. Step 3: Cross multiply
    405.51x = 559.90 × 280.96
  4. Step 4: Simplify right side
    405.51x = 157,309.50
  5. Step 5: Solve for x
    x = 157,309.50/405.51
  6. Step 6: Final answer
    x = 387.93

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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.