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Finding the Fourth Proportional to 127.28, 175.20 and 120.80

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Solution

The fourth proportional to 127.28, 175.20 and 120.80 is: 166.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.28 : 175.20 = 120.80 : x
  2. Step 2: Convert to fraction form
    127.28/175.20 = 120.80/x
  3. Step 3: Cross multiply
    127.28x = 175.20 × 120.80
  4. Step 4: Simplify right side
    127.28x = 21,164.16
  5. Step 5: Solve for x
    x = 21,164.16/127.28
  6. Step 6: Final answer
    x = 166.28

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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.