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Finding the Fourth Proportional to 19.98, 29.81 and 19.20

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Solution

The fourth proportional to 19.98, 29.81 and 19.20 is: 28.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.98 : 29.81 = 19.20 : x
  2. Step 2: Convert to fraction form
    19.98/29.81 = 19.20/x
  3. Step 3: Cross multiply
    19.98x = 29.81 × 19.20
  4. Step 4: Simplify right side
    19.98x = 572.26
  5. Step 5: Solve for x
    x = 572.26/19.98
  6. Step 6: Final answer
    x = 28.64

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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.