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Finding the Fourth Proportional to 143.05, 197.42 and 87.78

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Solution

The fourth proportional to 143.05, 197.42 and 87.78 is: 121.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.05 : 197.42 = 87.78 : x
  2. Step 2: Convert to fraction form
    143.05/197.42 = 87.78/x
  3. Step 3: Cross multiply
    143.05x = 197.42 × 87.78
  4. Step 4: Simplify right side
    143.05x = 17,329.53
  5. Step 5: Solve for x
    x = 17,329.53/143.05
  6. Step 6: Final answer
    x = 121.14

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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.