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Finding the Fourth Proportional to 406.85, 561.21 and 288.66

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Solution

The fourth proportional to 406.85, 561.21 and 288.66 is: 398.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.85 : 561.21 = 288.66 : x
  2. Step 2: Convert to fraction form
    406.85/561.21 = 288.66/x
  3. Step 3: Cross multiply
    406.85x = 561.21 × 288.66
  4. Step 4: Simplify right side
    406.85x = 161,998.88
  5. Step 5: Solve for x
    x = 161,998.88/406.85
  6. Step 6: Final answer
    x = 398.18

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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.