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Finding the Fourth Proportional to 19.98, 30.12 and 19.78

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Solution

The fourth proportional to 19.98, 30.12 and 19.78 is: 29.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.98 : 30.12 = 19.78 : x
  2. Step 2: Convert to fraction form
    19.98/30.12 = 19.78/x
  3. Step 3: Cross multiply
    19.98x = 30.12 × 19.78
  4. Step 4: Simplify right side
    19.98x = 595.77
  5. Step 5: Solve for x
    x = 595.77/19.98
  6. Step 6: Final answer
    x = 29.82

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.