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Finding the Fourth Proportional to 85.16, 127.80 and 79.70

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Solution

The fourth proportional to 85.16, 127.80 and 79.70 is: 119.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.16 : 127.80 = 79.70 : x
  2. Step 2: Convert to fraction form
    85.16/127.80 = 79.70/x
  3. Step 3: Cross multiply
    85.16x = 127.80 × 79.70
  4. Step 4: Simplify right side
    85.16x = 10,185.66
  5. Step 5: Solve for x
    x = 10,185.66/85.16
  6. Step 6: Final answer
    x = 119.61

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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.