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Finding the Fourth Proportional to 38.40, 57.60 and 30.48

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Solution

The fourth proportional to 38.40, 57.60 and 30.48 is: 45.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.40 : 57.60 = 30.48 : x
  2. Step 2: Convert to fraction form
    38.40/57.60 = 30.48/x
  3. Step 3: Cross multiply
    38.40x = 57.60 × 30.48
  4. Step 4: Simplify right side
    38.40x = 1,755.65
  5. Step 5: Solve for x
    x = 1,755.65/38.40
  6. Step 6: Final answer
    x = 45.72

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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.