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Finding the Fourth Proportional to 166.78, 249.90 and 139.78

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Solution

The fourth proportional to 166.78, 249.90 and 139.78 is: 209.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    166.78 : 249.90 = 139.78 : x
  2. Step 2: Convert to fraction form
    166.78/249.90 = 139.78/x
  3. Step 3: Cross multiply
    166.78x = 249.90 × 139.78
  4. Step 4: Simplify right side
    166.78x = 34,931.02
  5. Step 5: Solve for x
    x = 34,931.02/166.78
  6. Step 6: Final answer
    x = 209.44

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.