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Finding the Fourth Proportional to 76.85, 115.15 and 68.19

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Solution

The fourth proportional to 76.85, 115.15 and 68.19 is: 102.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.85 : 115.15 = 68.19 : x
  2. Step 2: Convert to fraction form
    76.85/115.15 = 68.19/x
  3. Step 3: Cross multiply
    76.85x = 115.15 × 68.19
  4. Step 4: Simplify right side
    76.85x = 7,852.08
  5. Step 5: Solve for x
    x = 7,852.08/76.85
  6. Step 6: Final answer
    x = 102.17

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.