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Finding the Fourth Proportional to 9.21, 13.76 and 7.31

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Solution

The fourth proportional to 9.21, 13.76 and 7.31 is: 10.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.21 : 13.76 = 7.31 : x
  2. Step 2: Convert to fraction form
    9.21/13.76 = 7.31/x
  3. Step 3: Cross multiply
    9.21x = 13.76 × 7.31
  4. Step 4: Simplify right side
    9.21x = 100.48
  5. Step 5: Solve for x
    x = 100.48/9.21
  6. Step 6: Final answer
    x = 10.91

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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.