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Finding the Fourth Proportional to 441.20, 661.20 and 389.60

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Solution

The fourth proportional to 441.20, 661.20 and 389.60 is: 583.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    441.20 : 661.20 = 389.60 : x
  2. Step 2: Convert to fraction form
    441.20/661.20 = 389.60/x
  3. Step 3: Cross multiply
    441.20x = 661.20 × 389.60
  4. Step 4: Simplify right side
    441.20x = 257,603.52
  5. Step 5: Solve for x
    x = 257,603.52/441.20
  6. Step 6: Final answer
    x = 583.87

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.