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Finding the Fourth Proportional to 38.40, 57.36 and 31.62

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Solution

The fourth proportional to 38.40, 57.36 and 31.62 is: 47.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.40 : 57.36 = 31.62 : x
  2. Step 2: Convert to fraction form
    38.40/57.36 = 31.62/x
  3. Step 3: Cross multiply
    38.40x = 57.36 × 31.62
  4. Step 4: Simplify right side
    38.40x = 1,813.72
  5. Step 5: Solve for x
    x = 1,813.72/38.40
  6. Step 6: Final answer
    x = 47.23

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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.