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Finding the Fourth Proportional to 208.09, 287.21 and 120.77

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Solution

The fourth proportional to 208.09, 287.21 and 120.77 is: 166.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.09 : 287.21 = 120.77 : x
  2. Step 2: Convert to fraction form
    208.09/287.21 = 120.77/x
  3. Step 3: Cross multiply
    208.09x = 287.21 × 120.77
  4. Step 4: Simplify right side
    208.09x = 34,685.75
  5. Step 5: Solve for x
    x = 34,685.75/208.09
  6. Step 6: Final answer
    x = 166.69

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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.