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Finding the Fourth Proportional to 121.30, 181.65 and 77.83

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Solution

The fourth proportional to 121.30, 181.65 and 77.83 is: 116.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.30 : 181.65 = 77.83 : x
  2. Step 2: Convert to fraction form
    121.30/181.65 = 77.83/x
  3. Step 3: Cross multiply
    121.30x = 181.65 × 77.83
  4. Step 4: Simplify right side
    121.30x = 14,136.99
  5. Step 5: Solve for x
    x = 14,136.99/121.30
  6. Step 6: Final answer
    x = 116.55

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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.