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Finding the Fourth Proportional to 170.78, 255.62 and 138.38

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Solution

The fourth proportional to 170.78, 255.62 and 138.38 is: 207.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    170.78 : 255.62 = 138.38 : x
  2. Step 2: Convert to fraction form
    170.78/255.62 = 138.38/x
  3. Step 3: Cross multiply
    170.78x = 255.62 × 138.38
  4. Step 4: Simplify right side
    170.78x = 35,371.76
  5. Step 5: Solve for x
    x = 35,371.76/170.78
  6. Step 6: Final answer
    x = 207.12

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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.