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Finding the Fourth Proportional to 42.18, 57.80 and 40.56

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Solution

The fourth proportional to 42.18, 57.80 and 40.56 is: 55.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.18 : 57.80 = 40.56 : x
  2. Step 2: Convert to fraction form
    42.18/57.80 = 40.56/x
  3. Step 3: Cross multiply
    42.18x = 57.80 × 40.56
  4. Step 4: Simplify right side
    42.18x = 2,344.17
  5. Step 5: Solve for x
    x = 2,344.17/42.18
  6. Step 6: Final answer
    x = 55.58

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.