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Finding the Fourth Proportional to 76.19, 105.28 and 66.65

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Solution

The fourth proportional to 76.19, 105.28 and 66.65 is: 92.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.19 : 105.28 = 66.65 : x
  2. Step 2: Convert to fraction form
    76.19/105.28 = 66.65/x
  3. Step 3: Cross multiply
    76.19x = 105.28 × 66.65
  4. Step 4: Simplify right side
    76.19x = 7,016.22
  5. Step 5: Solve for x
    x = 7,016.22/76.19
  6. Step 6: Final answer
    x = 92.09

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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.