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Finding the Fourth Proportional to 378.66, 522.55 and 221.33

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Solution

The fourth proportional to 378.66, 522.55 and 221.33 is: 305.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.66 : 522.55 = 221.33 : x
  2. Step 2: Convert to fraction form
    378.66/522.55 = 221.33/x
  3. Step 3: Cross multiply
    378.66x = 522.55 × 221.33
  4. Step 4: Simplify right side
    378.66x = 115,655.99
  5. Step 5: Solve for x
    x = 115,655.99/378.66
  6. Step 6: Final answer
    x = 305.43

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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.