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Finding the Fourth Proportional to 123.20, 170.31 and 118.28

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Solution

The fourth proportional to 123.20, 170.31 and 118.28 is: 163.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.20 : 170.31 = 118.28 : x
  2. Step 2: Convert to fraction form
    123.20/170.31 = 118.28/x
  3. Step 3: Cross multiply
    123.20x = 170.31 × 118.28
  4. Step 4: Simplify right side
    123.20x = 20,144.27
  5. Step 5: Solve for x
    x = 20,144.27/123.20
  6. Step 6: Final answer
    x = 163.51

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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.