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Finding the Fourth Proportional to 74.28, 102.42 and 57.90

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Solution

The fourth proportional to 74.28, 102.42 and 57.90 is: 79.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.28 : 102.42 = 57.90 : x
  2. Step 2: Convert to fraction form
    74.28/102.42 = 57.90/x
  3. Step 3: Cross multiply
    74.28x = 102.42 × 57.90
  4. Step 4: Simplify right side
    74.28x = 5,930.12
  5. Step 5: Solve for x
    x = 5,930.12/74.28
  6. Step 6: Final answer
    x = 79.83

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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.