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Finding the Fourth Proportional to 439.28, 661.26 and 399.60

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Solution

The fourth proportional to 439.28, 661.26 and 399.60 is: 601.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.28 : 661.26 = 399.60 : x
  2. Step 2: Convert to fraction form
    439.28/661.26 = 399.60/x
  3. Step 3: Cross multiply
    439.28x = 661.26 × 399.60
  4. Step 4: Simplify right side
    439.28x = 264,239.50
  5. Step 5: Solve for x
    x = 264,239.50/439.28
  6. Step 6: Final answer
    x = 601.53

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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.