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Finding the Fourth Proportional to 121.61, 180.96 and 121.21

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Solution

The fourth proportional to 121.61, 180.96 and 121.21 is: 180.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.61 : 180.96 = 121.21 : x
  2. Step 2: Convert to fraction form
    121.61/180.96 = 121.21/x
  3. Step 3: Cross multiply
    121.61x = 180.96 × 121.21
  4. Step 4: Simplify right side
    121.61x = 21,934.16
  5. Step 5: Solve for x
    x = 21,934.16/121.61
  6. Step 6: Final answer
    x = 180.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.