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Finding the Fourth Proportional to 378.64, 522.36 and 221.22

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Solution

The fourth proportional to 378.64, 522.36 and 221.22 is: 305.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.64 : 522.36 = 221.22 : x
  2. Step 2: Convert to fraction form
    378.64/522.36 = 221.22/x
  3. Step 3: Cross multiply
    378.64x = 522.36 × 221.22
  4. Step 4: Simplify right side
    378.64x = 115,556.48
  5. Step 5: Solve for x
    x = 115,556.48/378.64
  6. Step 6: Final answer
    x = 305.19

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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.