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Finding the Fourth Proportional to 208.36, 312.13 and 138.97

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Solution

The fourth proportional to 208.36, 312.13 and 138.97 is: 208.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.36 : 312.13 = 138.97 : x
  2. Step 2: Convert to fraction form
    208.36/312.13 = 138.97/x
  3. Step 3: Cross multiply
    208.36x = 312.13 × 138.97
  4. Step 4: Simplify right side
    208.36x = 43,376.71
  5. Step 5: Solve for x
    x = 43,376.71/208.36
  6. Step 6: Final answer
    x = 208.18

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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.