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Finding the Fourth Proportional to 38.79, 58.16 and 20.49

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Solution

The fourth proportional to 38.79, 58.16 and 20.49 is: 30.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.79 : 58.16 = 20.49 : x
  2. Step 2: Convert to fraction form
    38.79/58.16 = 20.49/x
  3. Step 3: Cross multiply
    38.79x = 58.16 × 20.49
  4. Step 4: Simplify right side
    38.79x = 1,191.31
  5. Step 5: Solve for x
    x = 1,191.31/38.79
  6. Step 6: Final answer
    x = 30.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.