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Finding the Fourth Proportional to 305.75, 421.94 and 218.57

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Solution

The fourth proportional to 305.75, 421.94 and 218.57 is: 301.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.75 : 421.94 = 218.57 : x
  2. Step 2: Convert to fraction form
    305.75/421.94 = 218.57/x
  3. Step 3: Cross multiply
    305.75x = 421.94 × 218.57
  4. Step 4: Simplify right side
    305.75x = 92,223.43
  5. Step 5: Solve for x
    x = 92,223.43/305.75
  6. Step 6: Final answer
    x = 301.63

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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.