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Finding the Fourth Proportional to 128.04, 176.82 and 91.20

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Solution

The fourth proportional to 128.04, 176.82 and 91.20 is: 125.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.04 : 176.82 = 91.20 : x
  2. Step 2: Convert to fraction form
    128.04/176.82 = 91.20/x
  3. Step 3: Cross multiply
    128.04x = 176.82 × 91.20
  4. Step 4: Simplify right side
    128.04x = 16,125.98
  5. Step 5: Solve for x
    x = 16,125.98/128.04
  6. Step 6: Final answer
    x = 125.94

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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.