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Finding the Fourth Proportional to 209.78, 289.52 and 131.15

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Solution

The fourth proportional to 209.78, 289.52 and 131.15 is: 181.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.78 : 289.52 = 131.15 : x
  2. Step 2: Convert to fraction form
    209.78/289.52 = 131.15/x
  3. Step 3: Cross multiply
    209.78x = 289.52 × 131.15
  4. Step 4: Simplify right side
    209.78x = 37,970.55
  5. Step 5: Solve for x
    x = 37,970.55/209.78
  6. Step 6: Final answer
    x = 181.00

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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.