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Finding the Fourth Proportional to 208.38, 287.55 and 115.13

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Solution

The fourth proportional to 208.38, 287.55 and 115.13 is: 158.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.38 : 287.55 = 115.13 : x
  2. Step 2: Convert to fraction form
    208.38/287.55 = 115.13/x
  3. Step 3: Cross multiply
    208.38x = 287.55 × 115.13
  4. Step 4: Simplify right side
    208.38x = 33,104.19
  5. Step 5: Solve for x
    x = 33,104.19/208.38
  6. Step 6: Final answer
    x = 158.86

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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.