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Finding the Fourth Proportional to 28.29, 42.37 and 20.72

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Solution

The fourth proportional to 28.29, 42.37 and 20.72 is: 31.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.29 : 42.37 = 20.72 : x
  2. Step 2: Convert to fraction form
    28.29/42.37 = 20.72/x
  3. Step 3: Cross multiply
    28.29x = 42.37 × 20.72
  4. Step 4: Simplify right side
    28.29x = 877.80
  5. Step 5: Solve for x
    x = 877.80/28.29
  6. Step 6: Final answer
    x = 31.03

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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.