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Finding the Fourth Proportional to 28.50, 42.81 and 19.99

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Solution

The fourth proportional to 28.50, 42.81 and 19.99 is: 30.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.50 : 42.81 = 19.99 : x
  2. Step 2: Convert to fraction form
    28.50/42.81 = 19.99/x
  3. Step 3: Cross multiply
    28.50x = 42.81 × 19.99
  4. Step 4: Simplify right side
    28.50x = 855.77
  5. Step 5: Solve for x
    x = 855.77/28.50
  6. Step 6: Final answer
    x = 30.03

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.