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Finding the Fourth Proportional to 42.40, 58.80 and 41.20

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Solution

The fourth proportional to 42.40, 58.80 and 41.20 is: 57.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.40 : 58.80 = 41.20 : x
  2. Step 2: Convert to fraction form
    42.40/58.80 = 41.20/x
  3. Step 3: Cross multiply
    42.40x = 58.80 × 41.20
  4. Step 4: Simplify right side
    42.40x = 2,422.56
  5. Step 5: Solve for x
    x = 2,422.56/42.40
  6. Step 6: Final answer
    x = 57.14

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.