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Finding the Fourth Proportional to 275.20, 378.84 and 209.68

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Solution

The fourth proportional to 275.20, 378.84 and 209.68 is: 288.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    275.20 : 378.84 = 209.68 : x
  2. Step 2: Convert to fraction form
    275.20/378.84 = 209.68/x
  3. Step 3: Cross multiply
    275.20x = 378.84 × 209.68
  4. Step 4: Simplify right side
    275.20x = 79,435.17
  5. Step 5: Solve for x
    x = 79,435.17/275.20
  6. Step 6: Final answer
    x = 288.65

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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.