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Finding the Fourth Proportional to 13.99, 20.99 and 7.99

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Solution

The fourth proportional to 13.99, 20.99 and 7.99 is: 11.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.99 : 20.99 = 7.99 : x
  2. Step 2: Convert to fraction form
    13.99/20.99 = 7.99/x
  3. Step 3: Cross multiply
    13.99x = 20.99 × 7.99
  4. Step 4: Simplify right side
    13.99x = 167.71
  5. Step 5: Solve for x
    x = 167.71/13.99
  6. Step 6: Final answer
    x = 11.99

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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.