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Finding the Fourth Proportional to 25.60, 38.21 and 21.25

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Solution

The fourth proportional to 25.60, 38.21 and 21.25 is: 31.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.60 : 38.21 = 21.25 : x
  2. Step 2: Convert to fraction form
    25.60/38.21 = 21.25/x
  3. Step 3: Cross multiply
    25.60x = 38.21 × 21.25
  4. Step 4: Simplify right side
    25.60x = 811.96
  5. Step 5: Solve for x
    x = 811.96/25.60
  6. Step 6: Final answer
    x = 31.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.