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Finding the Fourth Proportional to 405.71, 559.96 and 287.85

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Solution

The fourth proportional to 405.71, 559.96 and 287.85 is: 397.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.71 : 559.96 = 287.85 : x
  2. Step 2: Convert to fraction form
    405.71/559.96 = 287.85/x
  3. Step 3: Cross multiply
    405.71x = 559.96 × 287.85
  4. Step 4: Simplify right side
    405.71x = 161,187.49
  5. Step 5: Solve for x
    x = 161,187.49/405.71
  6. Step 6: Final answer
    x = 397.30

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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.