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Finding the Fourth Proportional to 42.05, 57.90 and 35.90

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Solution

The fourth proportional to 42.05, 57.90 and 35.90 is: 49.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.05 : 57.90 = 35.90 : x
  2. Step 2: Convert to fraction form
    42.05/57.90 = 35.90/x
  3. Step 3: Cross multiply
    42.05x = 57.90 × 35.90
  4. Step 4: Simplify right side
    42.05x = 2,078.61
  5. Step 5: Solve for x
    x = 2,078.61/42.05
  6. Step 6: Final answer
    x = 49.43

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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.