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Finding the Fourth Proportional to 208.87, 288.15 and 121.51

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Solution

The fourth proportional to 208.87, 288.15 and 121.51 is: 167.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.87 : 288.15 = 121.51 : x
  2. Step 2: Convert to fraction form
    208.87/288.15 = 121.51/x
  3. Step 3: Cross multiply
    208.87x = 288.15 × 121.51
  4. Step 4: Simplify right side
    208.87x = 35,013.11
  5. Step 5: Solve for x
    x = 35,013.11/208.87
  6. Step 6: Final answer
    x = 167.63

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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.