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Finding the Fourth Proportional to 218.05, 300.75 and 139.42

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Solution

The fourth proportional to 218.05, 300.75 and 139.42 is: 192.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.05 : 300.75 = 139.42 : x
  2. Step 2: Convert to fraction form
    218.05/300.75 = 139.42/x
  3. Step 3: Cross multiply
    218.05x = 300.75 × 139.42
  4. Step 4: Simplify right side
    218.05x = 41,930.57
  5. Step 5: Solve for x
    x = 41,930.57/218.05
  6. Step 6: Final answer
    x = 192.30

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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.