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Finding the Fourth Proportional to 120.83, 181.48 and 100.78

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Solution

The fourth proportional to 120.83, 181.48 and 100.78 is: 151.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.83 : 181.48 = 100.78 : x
  2. Step 2: Convert to fraction form
    120.83/181.48 = 100.78/x
  3. Step 3: Cross multiply
    120.83x = 181.48 × 100.78
  4. Step 4: Simplify right side
    120.83x = 18,289.05
  5. Step 5: Solve for x
    x = 18,289.05/120.83
  6. Step 6: Final answer
    x = 151.36

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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.