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Finding the Fourth Proportional to 28.32, 39.08 and 21.79

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Solution

The fourth proportional to 28.32, 39.08 and 21.79 is: 30.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.32 : 39.08 = 21.79 : x
  2. Step 2: Convert to fraction form
    28.32/39.08 = 21.79/x
  3. Step 3: Cross multiply
    28.32x = 39.08 × 21.79
  4. Step 4: Simplify right side
    28.32x = 851.55
  5. Step 5: Solve for x
    x = 851.55/28.32
  6. Step 6: Final answer
    x = 30.07

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.