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Finding the Fourth Proportional to 84.28, 126.38 and 30.12

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Solution

The fourth proportional to 84.28, 126.38 and 30.12 is: 45.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.28 : 126.38 = 30.12 : x
  2. Step 2: Convert to fraction form
    84.28/126.38 = 30.12/x
  3. Step 3: Cross multiply
    84.28x = 126.38 × 30.12
  4. Step 4: Simplify right side
    84.28x = 3,806.57
  5. Step 5: Solve for x
    x = 3,806.57/84.28
  6. Step 6: Final answer
    x = 45.17

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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.