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Finding the Fourth Proportional to 154.88, 213.64 and 128.50

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Solution

The fourth proportional to 154.88, 213.64 and 128.50 is: 177.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.88 : 213.64 = 128.50 : x
  2. Step 2: Convert to fraction form
    154.88/213.64 = 128.50/x
  3. Step 3: Cross multiply
    154.88x = 213.64 × 128.50
  4. Step 4: Simplify right side
    154.88x = 27,451.88
  5. Step 5: Solve for x
    x = 27,451.88/154.88
  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.