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Finding the Fourth Proportional to 406.85, 561.27 and 319.78

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Solution

The fourth proportional to 406.85, 561.27 and 319.78 is: 441.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.85 : 561.27 = 319.78 : x
  2. Step 2: Convert to fraction form
    406.85/561.27 = 319.78/x
  3. Step 3: Cross multiply
    406.85x = 561.27 × 319.78
  4. Step 4: Simplify right side
    406.85x = 179,480.11
  5. Step 5: Solve for x
    x = 179,480.11/406.85
  6. Step 6: Final answer
    x = 441.15

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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.