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Finding the Fourth Proportional to 25.75, 38.80 and 21.57

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Solution

The fourth proportional to 25.75, 38.80 and 21.57 is: 32.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.75 : 38.80 = 21.57 : x
  2. Step 2: Convert to fraction form
    25.75/38.80 = 21.57/x
  3. Step 3: Cross multiply
    25.75x = 38.80 × 21.57
  4. Step 4: Simplify right side
    25.75x = 836.92
  5. Step 5: Solve for x
    x = 836.92/25.75
  6. Step 6: Final answer
    x = 32.50

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.