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Finding the Fourth Proportional to 85.70, 118.10 and 67.28

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Solution

The fourth proportional to 85.70, 118.10 and 67.28 is: 92.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.70 : 118.10 = 67.28 : x
  2. Step 2: Convert to fraction form
    85.70/118.10 = 67.28/x
  3. Step 3: Cross multiply
    85.70x = 118.10 × 67.28
  4. Step 4: Simplify right side
    85.70x = 7,945.77
  5. Step 5: Solve for x
    x = 7,945.77/85.70
  6. Step 6: Final answer
    x = 92.72

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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.