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Finding the Fourth Proportional to 85.42, 127.89 and 70.84

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Solution

The fourth proportional to 85.42, 127.89 and 70.84 is: 106.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.42 : 127.89 = 70.84 : x
  2. Step 2: Convert to fraction form
    85.42/127.89 = 70.84/x
  3. Step 3: Cross multiply
    85.42x = 127.89 × 70.84
  4. Step 4: Simplify right side
    85.42x = 9,059.73
  5. Step 5: Solve for x
    x = 9,059.73/85.42
  6. Step 6: Final answer
    x = 106.06

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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.