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Finding the Fourth Proportional to 13.02, 19.40 and 12.75

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Solution

The fourth proportional to 13.02, 19.40 and 12.75 is: 18.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.02 : 19.40 = 12.75 : x
  2. Step 2: Convert to fraction form
    13.02/19.40 = 12.75/x
  3. Step 3: Cross multiply
    13.02x = 19.40 × 12.75
  4. Step 4: Simplify right side
    13.02x = 247.29
  5. Step 5: Solve for x
    x = 247.29/13.02
  6. Step 6: Final answer
    x = 18.99

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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.