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Finding the Fourth Proportional to 25.56, 35.19 and 21.90

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Solution

The fourth proportional to 25.56, 35.19 and 21.90 is: 30.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.56 : 35.19 = 21.90 : x
  2. Step 2: Convert to fraction form
    25.56/35.19 = 21.90/x
  3. Step 3: Cross multiply
    25.56x = 35.19 × 21.90
  4. Step 4: Simplify right side
    25.56x = 770.66
  5. Step 5: Solve for x
    x = 770.66/25.56
  6. Step 6: Final answer
    x = 30.15

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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.