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Finding the Fourth Proportional to 399.08, 598.38 and 138.98

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Solution

The fourth proportional to 399.08, 598.38 and 138.98 is: 208.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.08 : 598.38 = 138.98 : x
  2. Step 2: Convert to fraction form
    399.08/598.38 = 138.98/x
  3. Step 3: Cross multiply
    399.08x = 598.38 × 138.98
  4. Step 4: Simplify right side
    399.08x = 83,162.85
  5. Step 5: Solve for x
    x = 83,162.85/399.08
  6. Step 6: Final answer
    x = 208.39

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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.