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Finding the Fourth Proportional to 208.30, 287.37 and 129.56

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Solution

The fourth proportional to 208.30, 287.37 and 129.56 is: 178.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.30 : 287.37 = 129.56 : x
  2. Step 2: Convert to fraction form
    208.30/287.37 = 129.56/x
  3. Step 3: Cross multiply
    208.30x = 287.37 × 129.56
  4. Step 4: Simplify right side
    208.30x = 37,231.66
  5. Step 5: Solve for x
    x = 37,231.66/208.30
  6. Step 6: Final answer
    x = 178.74

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.