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Finding the Fourth Proportional to 253.45, 380.85 and 221.70

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Solution

The fourth proportional to 253.45, 380.85 and 221.70 is: 333.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.45 : 380.85 = 221.70 : x
  2. Step 2: Convert to fraction form
    253.45/380.85 = 221.70/x
  3. Step 3: Cross multiply
    253.45x = 380.85 × 221.70
  4. Step 4: Simplify right side
    253.45x = 84,434.45
  5. Step 5: Solve for x
    x = 84,434.45/253.45
  6. Step 6: Final answer
    x = 333.15

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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.