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Finding the Fourth Proportional to 51.40, 77.28 and 45.12

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Solution

The fourth proportional to 51.40, 77.28 and 45.12 is: 67.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.40 : 77.28 = 45.12 : x
  2. Step 2: Convert to fraction form
    51.40/77.28 = 45.12/x
  3. Step 3: Cross multiply
    51.40x = 77.28 × 45.12
  4. Step 4: Simplify right side
    51.40x = 3,486.87
  5. Step 5: Solve for x
    x = 3,486.87/51.40
  6. Step 6: Final answer
    x = 67.84

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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.