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Finding the Fourth Proportional to 86.42, 119.25 and 55.31

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Solution

The fourth proportional to 86.42, 119.25 and 55.31 is: 76.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.42 : 119.25 = 55.31 : x
  2. Step 2: Convert to fraction form
    86.42/119.25 = 55.31/x
  3. Step 3: Cross multiply
    86.42x = 119.25 × 55.31
  4. Step 4: Simplify right side
    86.42x = 6,595.12
  5. Step 5: Solve for x
    x = 6,595.12/86.42
  6. Step 6: Final answer
    x = 76.32

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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.