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Finding the Fourth Proportional to 28.96, 39.98 and 19.80

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Solution

The fourth proportional to 28.96, 39.98 and 19.80 is: 27.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.96 : 39.98 = 19.80 : x
  2. Step 2: Convert to fraction form
    28.96/39.98 = 19.80/x
  3. Step 3: Cross multiply
    28.96x = 39.98 × 19.80
  4. Step 4: Simplify right side
    28.96x = 791.31
  5. Step 5: Solve for x
    x = 791.31/28.96
  6. Step 6: Final answer
    x = 27.32

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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.