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Finding the Fourth Proportional to 121.40, 182.16 and 80.81

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Solution

The fourth proportional to 121.40, 182.16 and 80.81 is: 121.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.40 : 182.16 = 80.81 : x
  2. Step 2: Convert to fraction form
    121.40/182.16 = 80.81/x
  3. Step 3: Cross multiply
    121.40x = 182.16 × 80.81
  4. Step 4: Simplify right side
    121.40x = 14,720.35
  5. Step 5: Solve for x
    x = 14,720.35/121.40
  6. Step 6: Final answer
    x = 121.25

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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.