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Finding the Fourth Proportional to 7.71, 11.57 and 3.21

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Solution

The fourth proportional to 7.71, 11.57 and 3.21 is: 4.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.71 : 11.57 = 3.21 : x
  2. Step 2: Convert to fraction form
    7.71/11.57 = 3.21/x
  3. Step 3: Cross multiply
    7.71x = 11.57 × 3.21
  4. Step 4: Simplify right side
    7.71x = 37.12
  5. Step 5: Solve for x
    x = 37.12/7.71
  6. Step 6: Final answer
    x = 4.82

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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.