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Finding the Fourth Proportional to 305.75, 421.70 and 212.49

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Solution

The fourth proportional to 305.75, 421.70 and 212.49 is: 293.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.75 : 421.70 = 212.49 : x
  2. Step 2: Convert to fraction form
    305.75/421.70 = 212.49/x
  3. Step 3: Cross multiply
    305.75x = 421.70 × 212.49
  4. Step 4: Simplify right side
    305.75x = 89,605.97
  5. Step 5: Solve for x
    x = 89,605.97/305.75
  6. Step 6: Final answer
    x = 293.07

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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.