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Finding the Fourth Proportional to 6.40, 8.89 and 6.38

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Solution

The fourth proportional to 6.40, 8.89 and 6.38 is: 8.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.40 : 8.89 = 6.38 : x
  2. Step 2: Convert to fraction form
    6.40/8.89 = 6.38/x
  3. Step 3: Cross multiply
    6.40x = 8.89 × 6.38
  4. Step 4: Simplify right side
    6.40x = 56.72
  5. Step 5: Solve for x
    x = 56.72/6.40
  6. Step 6: Final answer
    x = 8.86

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.