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Finding the Fourth Proportional to 121.34, 181.70 and 80.70

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Solution

The fourth proportional to 121.34, 181.70 and 80.70 is: 120.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.34 : 181.70 = 80.70 : x
  2. Step 2: Convert to fraction form
    121.34/181.70 = 80.70/x
  3. Step 3: Cross multiply
    121.34x = 181.70 × 80.70
  4. Step 4: Simplify right side
    121.34x = 14,663.19
  5. Step 5: Solve for x
    x = 14,663.19/121.34
  6. Step 6: Final answer
    x = 120.84

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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.