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Finding the Fourth Proportional to 120.89, 181.55 and 90.36

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Solution

The fourth proportional to 120.89, 181.55 and 90.36 is: 135.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.89 : 181.55 = 90.36 : x
  2. Step 2: Convert to fraction form
    120.89/181.55 = 90.36/x
  3. Step 3: Cross multiply
    120.89x = 181.55 × 90.36
  4. Step 4: Simplify right side
    120.89x = 16,405.08
  5. Step 5: Solve for x
    x = 16,405.08/120.89
  6. Step 6: Final answer
    x = 135.70

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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.