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Finding the Fourth Proportional to 378.67, 522.47 and 221.26

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Solution

The fourth proportional to 378.67, 522.47 and 221.26 is: 305.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.67 : 522.47 = 221.26 : x
  2. Step 2: Convert to fraction form
    378.67/522.47 = 221.26/x
  3. Step 3: Cross multiply
    378.67x = 522.47 × 221.26
  4. Step 4: Simplify right side
    378.67x = 115,601.71
  5. Step 5: Solve for x
    x = 115,601.71/378.67
  6. Step 6: Final answer
    x = 305.28

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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.