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Finding the Fourth Proportional to 378.40, 522.14 and 221.08

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Solution

The fourth proportional to 378.40, 522.14 and 221.08 is: 305.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.40 : 522.14 = 221.08 : x
  2. Step 2: Convert to fraction form
    378.40/522.14 = 221.08/x
  3. Step 3: Cross multiply
    378.40x = 522.14 × 221.08
  4. Step 4: Simplify right side
    378.40x = 115,431.00
  5. Step 5: Solve for x
    x = 115,431.00/378.40
  6. Step 6: Final answer
    x = 305.05

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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.