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Finding the Fourth Proportional to 208.80, 288.08 and 121.42

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Solution

The fourth proportional to 208.80, 288.08 and 121.42 is: 167.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.80 : 288.08 = 121.42 : x
  2. Step 2: Convert to fraction form
    208.80/288.08 = 121.42/x
  3. Step 3: Cross multiply
    208.80x = 288.08 × 121.42
  4. Step 4: Simplify right side
    208.80x = 34,978.67
  5. Step 5: Solve for x
    x = 34,978.67/208.80
  6. Step 6: Final answer
    x = 167.52

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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.