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Finding the Fourth Proportional to 209.51, 289.18 and 130.78

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Solution

The fourth proportional to 209.51, 289.18 and 130.78 is: 180.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.51 : 289.18 = 130.78 : x
  2. Step 2: Convert to fraction form
    209.51/289.18 = 130.78/x
  3. Step 3: Cross multiply
    209.51x = 289.18 × 130.78
  4. Step 4: Simplify right side
    209.51x = 37,818.96
  5. Step 5: Solve for x
    x = 37,818.96/209.51
  6. Step 6: Final answer
    x = 180.51

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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.