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Finding the Fourth Proportional to 121.28, 181.98 and 98.71

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Solution

The fourth proportional to 121.28, 181.98 and 98.71 is: 148.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.28 : 181.98 = 98.71 : x
  2. Step 2: Convert to fraction form
    121.28/181.98 = 98.71/x
  3. Step 3: Cross multiply
    121.28x = 181.98 × 98.71
  4. Step 4: Simplify right side
    121.28x = 17,963.33
  5. Step 5: Solve for x
    x = 17,963.33/121.28
  6. Step 6: Final answer
    x = 148.11

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.