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Finding the Fourth Proportional to 79.75, 109.92 and 65.89

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Solution

The fourth proportional to 79.75, 109.92 and 65.89 is: 90.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.75 : 109.92 = 65.89 : x
  2. Step 2: Convert to fraction form
    79.75/109.92 = 65.89/x
  3. Step 3: Cross multiply
    79.75x = 109.92 × 65.89
  4. Step 4: Simplify right side
    79.75x = 7,242.63
  5. Step 5: Solve for x
    x = 7,242.63/79.75
  6. Step 6: Final answer
    x = 90.82

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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.