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Finding the Fourth Proportional to 218.11, 300.90 and 139.45

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Solution

The fourth proportional to 218.11, 300.90 and 139.45 is: 192.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.11 : 300.90 = 139.45 : x
  2. Step 2: Convert to fraction form
    218.11/300.90 = 139.45/x
  3. Step 3: Cross multiply
    218.11x = 300.90 × 139.45
  4. Step 4: Simplify right side
    218.11x = 41,960.51
  5. Step 5: Solve for x
    x = 41,960.51/218.11
  6. Step 6: Final answer
    x = 192.38

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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.