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Finding the Fourth Proportional to 121.78, 182.37 and 103.69

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Solution

The fourth proportional to 121.78, 182.37 and 103.69 is: 155.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.78 : 182.37 = 103.69 : x
  2. Step 2: Convert to fraction form
    121.78/182.37 = 103.69/x
  3. Step 3: Cross multiply
    121.78x = 182.37 × 103.69
  4. Step 4: Simplify right side
    121.78x = 18,909.95
  5. Step 5: Solve for x
    x = 18,909.95/121.78
  6. Step 6: Final answer
    x = 155.28

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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.