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Finding the Fourth Proportional to 40.74, 55.81 and 39.20

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Solution

The fourth proportional to 40.74, 55.81 and 39.20 is: 53.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.74 : 55.81 = 39.20 : x
  2. Step 2: Convert to fraction form
    40.74/55.81 = 39.20/x
  3. Step 3: Cross multiply
    40.74x = 55.81 × 39.20
  4. Step 4: Simplify right side
    40.74x = 2,187.80
  5. Step 5: Solve for x
    x = 2,187.80/40.74
  6. Step 6: Final answer
    x = 53.70

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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.