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Finding the Fourth Proportional to 405.44, 611.20 and 378.66

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Solution

The fourth proportional to 405.44, 611.20 and 378.66 is: 570.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.44 : 611.20 = 378.66 : x
  2. Step 2: Convert to fraction form
    405.44/611.20 = 378.66/x
  3. Step 3: Cross multiply
    405.44x = 611.20 × 378.66
  4. Step 4: Simplify right side
    405.44x = 231,436.99
  5. Step 5: Solve for x
    x = 231,436.99/405.44
  6. Step 6: Final answer
    x = 570.83

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.