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Finding the Fourth Proportional to 143.12, 197.51 and 87.81

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Solution

The fourth proportional to 143.12, 197.51 and 87.81 is: 121.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.12 : 197.51 = 87.81 : x
  2. Step 2: Convert to fraction form
    143.12/197.51 = 87.81/x
  3. Step 3: Cross multiply
    143.12x = 197.51 × 87.81
  4. Step 4: Simplify right side
    143.12x = 17,342.91
  5. Step 5: Solve for x
    x = 17,342.91/143.12
  6. Step 6: Final answer
    x = 121.18

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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.