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Finding the Fourth Proportional to 305.78, 422.04 and 217.40

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Solution

The fourth proportional to 305.78, 422.04 and 217.40 is: 300.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.78 : 422.04 = 217.40 : x
  2. Step 2: Convert to fraction form
    305.78/422.04 = 217.40/x
  3. Step 3: Cross multiply
    305.78x = 422.04 × 217.40
  4. Step 4: Simplify right side
    305.78x = 91,749.39
  5. Step 5: Solve for x
    x = 91,749.39/305.78
  6. Step 6: Final answer
    x = 300.06

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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.