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Finding the Fourth Proportional to 143.28, 197.82 and 99.72

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Solution

The fourth proportional to 143.28, 197.82 and 99.72 is: 137.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.28 : 197.82 = 99.72 : x
  2. Step 2: Convert to fraction form
    143.28/197.82 = 99.72/x
  3. Step 3: Cross multiply
    143.28x = 197.82 × 99.72
  4. Step 4: Simplify right side
    143.28x = 19,726.61
  5. Step 5: Solve for x
    x = 19,726.61/143.28
  6. Step 6: Final answer
    x = 137.68

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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.