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Finding the Fourth Proportional to 60.91, 91.28 and 28.40

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Solution

The fourth proportional to 60.91, 91.28 and 28.40 is: 42.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    60.91 : 91.28 = 28.40 : x
  2. Step 2: Convert to fraction form
    60.91/91.28 = 28.40/x
  3. Step 3: Cross multiply
    60.91x = 91.28 × 28.40
  4. Step 4: Simplify right side
    60.91x = 2,591.97
  5. Step 5: Solve for x
    x = 2,591.97/60.91
  6. Step 6: Final answer
    x = 42.56

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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.