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Finding the Fourth Proportional to 25.40, 35.07 and 20.21

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Solution

The fourth proportional to 25.40, 35.07 and 20.21 is: 27.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.40 : 35.07 = 20.21 : x
  2. Step 2: Convert to fraction form
    25.40/35.07 = 20.21/x
  3. Step 3: Cross multiply
    25.40x = 35.07 × 20.21
  4. Step 4: Simplify right side
    25.40x = 708.76
  5. Step 5: Solve for x
    x = 708.76/25.40
  6. Step 6: Final answer
    x = 27.90

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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.