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Finding the Fourth Proportional to 275.90, 381.40 and 221.18

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Solution

The fourth proportional to 275.90, 381.40 and 221.18 is: 305.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    275.90 : 381.40 = 221.18 : x
  2. Step 2: Convert to fraction form
    275.90/381.40 = 221.18/x
  3. Step 3: Cross multiply
    275.90x = 381.40 × 221.18
  4. Step 4: Simplify right side
    275.90x = 84,358.05
  5. Step 5: Solve for x
    x = 84,358.05/275.90
  6. Step 6: Final answer
    x = 305.76

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.