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Finding the Fourth Proportional to 121.31, 181.64 and 91.94

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Solution

The fourth proportional to 121.31, 181.64 and 91.94 is: 137.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.31 : 181.64 = 91.94 : x
  2. Step 2: Convert to fraction form
    121.31/181.64 = 91.94/x
  3. Step 3: Cross multiply
    121.31x = 181.64 × 91.94
  4. Step 4: Simplify right side
    121.31x = 16,700.67
  5. Step 5: Solve for x
    x = 16,700.67/121.31
  6. Step 6: Final answer
    x = 137.67

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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.