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Finding the Fourth Proportional to 399.88, 599.60 and 139.86

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Solution

The fourth proportional to 399.88, 599.60 and 139.86 is: 209.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.88 : 599.60 = 139.86 : x
  2. Step 2: Convert to fraction form
    399.88/599.60 = 139.86/x
  3. Step 3: Cross multiply
    399.88x = 599.60 × 139.86
  4. Step 4: Simplify right side
    399.88x = 83,862.09
  5. Step 5: Solve for x
    x = 83,862.09/399.88
  6. Step 6: Final answer
    x = 209.72

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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.