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Finding the Fourth Proportional to 121.05, 181.98 and 85.23

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Solution

The fourth proportional to 121.05, 181.98 and 85.23 is: 128.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.05 : 181.98 = 85.23 : x
  2. Step 2: Convert to fraction form
    121.05/181.98 = 85.23/x
  3. Step 3: Cross multiply
    121.05x = 181.98 × 85.23
  4. Step 4: Simplify right side
    121.05x = 15,510.16
  5. Step 5: Solve for x
    x = 15,510.16/121.05
  6. Step 6: Final answer
    x = 128.13

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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.