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Finding the Fourth Proportional to 45.12, 67.28 and 40.80

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Solution

The fourth proportional to 45.12, 67.28 and 40.80 is: 60.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    45.12 : 67.28 = 40.80 : x
  2. Step 2: Convert to fraction form
    45.12/67.28 = 40.80/x
  3. Step 3: Cross multiply
    45.12x = 67.28 × 40.80
  4. Step 4: Simplify right side
    45.12x = 2,745.02
  5. Step 5: Solve for x
    x = 2,745.02/45.12
  6. Step 6: Final answer
    x = 60.84

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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.