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Finding the Fourth Proportional to 253.94, 380.90 and 80.60

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Solution

The fourth proportional to 253.94, 380.90 and 80.60 is: 120.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.94 : 380.90 = 80.60 : x
  2. Step 2: Convert to fraction form
    253.94/380.90 = 80.60/x
  3. Step 3: Cross multiply
    253.94x = 380.90 × 80.60
  4. Step 4: Simplify right side
    253.94x = 30,700.54
  5. Step 5: Solve for x
    x = 30,700.54/253.94
  6. Step 6: Final answer
    x = 120.90

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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.