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Finding the Fourth Proportional to 19.21, 28.81 and 7.18

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Solution

The fourth proportional to 19.21, 28.81 and 7.18 is: 10.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.21 : 28.81 = 7.18 : x
  2. Step 2: Convert to fraction form
    19.21/28.81 = 7.18/x
  3. Step 3: Cross multiply
    19.21x = 28.81 × 7.18
  4. Step 4: Simplify right side
    19.21x = 206.86
  5. Step 5: Solve for x
    x = 206.86/19.21
  6. Step 6: Final answer
    x = 10.77

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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.