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Finding the Fourth Proportional to 128.98, 193.38 and 92.85

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Solution

The fourth proportional to 128.98, 193.38 and 92.85 is: 139.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.98 : 193.38 = 92.85 : x
  2. Step 2: Convert to fraction form
    128.98/193.38 = 92.85/x
  3. Step 3: Cross multiply
    128.98x = 193.38 × 92.85
  4. Step 4: Simplify right side
    128.98x = 17,955.33
  5. Step 5: Solve for x
    x = 17,955.33/128.98
  6. Step 6: Final answer
    x = 139.21

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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.