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Finding the Fourth Proportional to 86.79, 119.69 and 75.13

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Solution

The fourth proportional to 86.79, 119.69 and 75.13 is: 103.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.79 : 119.69 = 75.13 : x
  2. Step 2: Convert to fraction form
    86.79/119.69 = 75.13/x
  3. Step 3: Cross multiply
    86.79x = 119.69 × 75.13
  4. Step 4: Simplify right side
    86.79x = 8,991.93
  5. Step 5: Solve for x
    x = 8,991.93/86.79
  6. Step 6: Final answer
    x = 103.60

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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.