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Finding the Fourth Proportional to 28.30, 42.42 and 19.72

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Solution

The fourth proportional to 28.30, 42.42 and 19.72 is: 29.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.30 : 42.42 = 19.72 : x
  2. Step 2: Convert to fraction form
    28.30/42.42 = 19.72/x
  3. Step 3: Cross multiply
    28.30x = 42.42 × 19.72
  4. Step 4: Simplify right side
    28.30x = 836.52
  5. Step 5: Solve for x
    x = 836.52/28.30
  6. Step 6: Final answer
    x = 29.56

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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.