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Finding the Fourth Proportional to 38.40, 57.32 and 30.72

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Solution

The fourth proportional to 38.40, 57.32 and 30.72 is: 45.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.40 : 57.32 = 30.72 : x
  2. Step 2: Convert to fraction form
    38.40/57.32 = 30.72/x
  3. Step 3: Cross multiply
    38.40x = 57.32 × 30.72
  4. Step 4: Simplify right side
    38.40x = 1,760.87
  5. Step 5: Solve for x
    x = 1,760.87/38.40
  6. Step 6: Final answer
    x = 45.86

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.