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Finding the Fourth Proportional to 7.15, 9.85 and 6.87

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Solution

The fourth proportional to 7.15, 9.85 and 6.87 is: 9.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.15 : 9.85 = 6.87 : x
  2. Step 2: Convert to fraction form
    7.15/9.85 = 6.87/x
  3. Step 3: Cross multiply
    7.15x = 9.85 × 6.87
  4. Step 4: Simplify right side
    7.15x = 67.67
  5. Step 5: Solve for x
    x = 67.67/7.15
  6. Step 6: Final answer
    x = 9.46

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.