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Finding the Fourth Proportional to 20.30, 30.21 and 19.45

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Solution

The fourth proportional to 20.30, 30.21 and 19.45 is: 28.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.30 : 30.21 = 19.45 : x
  2. Step 2: Convert to fraction form
    20.30/30.21 = 19.45/x
  3. Step 3: Cross multiply
    20.30x = 30.21 × 19.45
  4. Step 4: Simplify right side
    20.30x = 587.51
  5. Step 5: Solve for x
    x = 587.51/20.30
  6. Step 6: Final answer
    x = 28.95

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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.