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Finding the Fourth Proportional to 57.57, 79.50 and 39.20

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Solution

The fourth proportional to 57.57, 79.50 and 39.20 is: 54.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.57 : 79.50 = 39.20 : x
  2. Step 2: Convert to fraction form
    57.57/79.50 = 39.20/x
  3. Step 3: Cross multiply
    57.57x = 79.50 × 39.20
  4. Step 4: Simplify right side
    57.57x = 3,116.15
  5. Step 5: Solve for x
    x = 3,116.15/57.57
  6. Step 6: Final answer
    x = 54.13

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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.