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Finding the Fourth Proportional to 86.12, 118.86 and 65.36

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Solution

The fourth proportional to 86.12, 118.86 and 65.36 is: 90.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.12 : 118.86 = 65.36 : x
  2. Step 2: Convert to fraction form
    86.12/118.86 = 65.36/x
  3. Step 3: Cross multiply
    86.12x = 118.86 × 65.36
  4. Step 4: Simplify right side
    86.12x = 7,768.52
  5. Step 5: Solve for x
    x = 7,768.52/86.12
  6. Step 6: Final answer
    x = 90.21

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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.