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Finding the Fourth Proportional to 209.31, 288.90 and 130.70

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Solution

The fourth proportional to 209.31, 288.90 and 130.70 is: 180.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.31 : 288.90 = 130.70 : x
  2. Step 2: Convert to fraction form
    209.31/288.90 = 130.70/x
  3. Step 3: Cross multiply
    209.31x = 288.90 × 130.70
  4. Step 4: Simplify right side
    209.31x = 37,757.79
  5. Step 5: Solve for x
    x = 37,757.79/209.31
  6. Step 6: Final answer
    x = 180.39

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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.