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Finding the Fourth Proportional to 13.28, 18.30 and 8.42

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Solution

The fourth proportional to 13.28, 18.30 and 8.42 is: 11.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.28 : 18.30 = 8.42 : x
  2. Step 2: Convert to fraction form
    13.28/18.30 = 8.42/x
  3. Step 3: Cross multiply
    13.28x = 18.30 × 8.42
  4. Step 4: Simplify right side
    13.28x = 153.99
  5. Step 5: Solve for x
    x = 153.99/13.28
  6. Step 6: Final answer
    x = 11.60

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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.