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Finding the Fourth Proportional to 57.45, 79.31 and 39.98

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Solution

The fourth proportional to 57.45, 79.31 and 39.98 is: 55.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.45 : 79.31 = 39.98 : x
  2. Step 2: Convert to fraction form
    57.45/79.31 = 39.98/x
  3. Step 3: Cross multiply
    57.45x = 79.31 × 39.98
  4. Step 4: Simplify right side
    57.45x = 3,170.22
  5. Step 5: Solve for x
    x = 3,170.22/57.45
  6. Step 6: Final answer
    x = 55.18

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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.