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Finding the Fourth Proportional to 399.72, 599.64 and 139.64

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Solution

The fourth proportional to 399.72, 599.64 and 139.64 is: 209.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.72 : 599.64 = 139.64 : x
  2. Step 2: Convert to fraction form
    399.72/599.64 = 139.64/x
  3. Step 3: Cross multiply
    399.72x = 599.64 × 139.64
  4. Step 4: Simplify right side
    399.72x = 83,733.73
  5. Step 5: Solve for x
    x = 83,733.73/399.72
  6. Step 6: Final answer
    x = 209.48

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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.