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Finding the Fourth Proportional to 128.04, 191.88 and 63.78

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Solution

The fourth proportional to 128.04, 191.88 and 63.78 is: 95.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.04 : 191.88 = 63.78 : x
  2. Step 2: Convert to fraction form
    128.04/191.88 = 63.78/x
  3. Step 3: Cross multiply
    128.04x = 191.88 × 63.78
  4. Step 4: Simplify right side
    128.04x = 12,238.11
  5. Step 5: Solve for x
    x = 12,238.11/128.04
  6. Step 6: Final answer
    x = 95.58

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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.