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Finding the Fourth Proportional to 25.87, 35.71 and 21.31

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Solution

The fourth proportional to 25.87, 35.71 and 21.31 is: 29.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.87 : 35.71 = 21.31 : x
  2. Step 2: Convert to fraction form
    25.87/35.71 = 21.31/x
  3. Step 3: Cross multiply
    25.87x = 35.71 × 21.31
  4. Step 4: Simplify right side
    25.87x = 760.98
  5. Step 5: Solve for x
    x = 760.98/25.87
  6. Step 6: Final answer
    x = 29.42

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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.