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Finding the Fourth Proportional to 154.75, 213.37 and 128.55

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Solution

The fourth proportional to 154.75, 213.37 and 128.55 is: 177.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.75 : 213.37 = 128.55 : x
  2. Step 2: Convert to fraction form
    154.75/213.37 = 128.55/x
  3. Step 3: Cross multiply
    154.75x = 213.37 × 128.55
  4. Step 4: Simplify right side
    154.75x = 27,428.07
  5. Step 5: Solve for x
    x = 27,428.07/154.75
  6. Step 6: Final answer
    x = 177.25

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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.