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Finding the Fourth Proportional to 208.29, 287.45 and 115.05

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Solution

The fourth proportional to 208.29, 287.45 and 115.05 is: 158.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.29 : 287.45 = 115.05 : x
  2. Step 2: Convert to fraction form
    208.29/287.45 = 115.05/x
  3. Step 3: Cross multiply
    208.29x = 287.45 × 115.05
  4. Step 4: Simplify right side
    208.29x = 33,070.55
  5. Step 5: Solve for x
    x = 33,070.55/208.29
  6. Step 6: Final answer
    x = 158.78

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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.