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Finding the Fourth Proportional to 57.78, 79.68 and 40.50

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Solution

The fourth proportional to 57.78, 79.68 and 40.50 is: 55.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.78 : 79.68 = 40.50 : x
  2. Step 2: Convert to fraction form
    57.78/79.68 = 40.50/x
  3. Step 3: Cross multiply
    57.78x = 79.68 × 40.50
  4. Step 4: Simplify right side
    57.78x = 3,227.04
  5. Step 5: Solve for x
    x = 3,227.04/57.78
  6. Step 6: Final answer
    x = 55.85

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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.