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Finding the Fourth Proportional to 166.40, 249.56 and 85.20

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Solution

The fourth proportional to 166.40, 249.56 and 85.20 is: 127.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    166.40 : 249.56 = 85.20 : x
  2. Step 2: Convert to fraction form
    166.40/249.56 = 85.20/x
  3. Step 3: Cross multiply
    166.40x = 249.56 × 85.20
  4. Step 4: Simplify right side
    166.40x = 21,262.51
  5. Step 5: Solve for x
    x = 21,262.51/166.40
  6. Step 6: Final answer
    x = 127.78

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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.