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Finding the Fourth Proportional to 11.02, 15.21 and 7.78

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Solution

The fourth proportional to 11.02, 15.21 and 7.78 is: 10.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.02 : 15.21 = 7.78 : x
  2. Step 2: Convert to fraction form
    11.02/15.21 = 7.78/x
  3. Step 3: Cross multiply
    11.02x = 15.21 × 7.78
  4. Step 4: Simplify right side
    11.02x = 118.33
  5. Step 5: Solve for x
    x = 118.33/11.02
  6. Step 6: Final answer
    x = 10.74

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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.