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Finding the Fourth Proportional to 9.78, 13.44 and 8.16

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Solution

The fourth proportional to 9.78, 13.44 and 8.16 is: 11.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.78 : 13.44 = 8.16 : x
  2. Step 2: Convert to fraction form
    9.78/13.44 = 8.16/x
  3. Step 3: Cross multiply
    9.78x = 13.44 × 8.16
  4. Step 4: Simplify right side
    9.78x = 109.67
  5. Step 5: Solve for x
    x = 109.67/9.78
  6. Step 6: Final answer
    x = 11.21

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.