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Finding the Fourth Proportional to 8.91, 13.42 and 6.40

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Solution

The fourth proportional to 8.91, 13.42 and 6.40 is: 9.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.91 : 13.42 = 6.40 : x
  2. Step 2: Convert to fraction form
    8.91/13.42 = 6.40/x
  3. Step 3: Cross multiply
    8.91x = 13.42 × 6.40
  4. Step 4: Simplify right side
    8.91x = 85.83
  5. Step 5: Solve for x
    x = 85.83/8.91
  6. Step 6: Final answer
    x = 9.63

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.