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Finding the Fourth Proportional to 28.25, 38.99 and 15.31

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Solution

The fourth proportional to 28.25, 38.99 and 15.31 is: 21.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.25 : 38.99 = 15.31 : x
  2. Step 2: Convert to fraction form
    28.25/38.99 = 15.31/x
  3. Step 3: Cross multiply
    28.25x = 38.99 × 15.31
  4. Step 4: Simplify right side
    28.25x = 596.96
  5. Step 5: Solve for x
    x = 596.96/28.25
  6. Step 6: Final answer
    x = 21.13

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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.