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Finding the Fourth Proportional to 128.30, 191.22 and 100.76

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Solution

The fourth proportional to 128.30, 191.22 and 100.76 is: 150.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.30 : 191.22 = 100.76 : x
  2. Step 2: Convert to fraction form
    128.30/191.22 = 100.76/x
  3. Step 3: Cross multiply
    128.30x = 191.22 × 100.76
  4. Step 4: Simplify right side
    128.30x = 19,265.99
  5. Step 5: Solve for x
    x = 19,265.99/128.30
  6. Step 6: Final answer
    x = 150.17

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.