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Finding the Fourth Proportional to 11.51, 15.88 and 7.87

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Solution

The fourth proportional to 11.51, 15.88 and 7.87 is: 10.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.51 : 15.88 = 7.87 : x
  2. Step 2: Convert to fraction form
    11.51/15.88 = 7.87/x
  3. Step 3: Cross multiply
    11.51x = 15.88 × 7.87
  4. Step 4: Simplify right side
    11.51x = 124.86
  5. Step 5: Solve for x
    x = 124.86/11.51
  6. Step 6: Final answer
    x = 10.85

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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.