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Finding the Fourth Proportional to 86.60, 119.60 and 79.31

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Solution

The fourth proportional to 86.60, 119.60 and 79.31 is: 109.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.60 : 119.60 = 79.31 : x
  2. Step 2: Convert to fraction form
    86.60/119.60 = 79.31/x
  3. Step 3: Cross multiply
    86.60x = 119.60 × 79.31
  4. Step 4: Simplify right side
    86.60x = 9,484.48
  5. Step 5: Solve for x
    x = 9,484.48/86.60
  6. Step 6: Final answer
    x = 109.53

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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.