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Finding the Fourth Proportional to 57.45, 79.20 and 45.78

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Solution

The fourth proportional to 57.45, 79.20 and 45.78 is: 63.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.45 : 79.20 = 45.78 : x
  2. Step 2: Convert to fraction form
    57.45/79.20 = 45.78/x
  3. Step 3: Cross multiply
    57.45x = 79.20 × 45.78
  4. Step 4: Simplify right side
    57.45x = 3,625.78
  5. Step 5: Solve for x
    x = 3,625.78/57.45
  6. Step 6: Final answer
    x = 63.11

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.