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Finding the Fourth Proportional to 309.89, 427.65 and 199.43

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Solution

The fourth proportional to 309.89, 427.65 and 199.43 is: 275.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.89 : 427.65 = 199.43 : x
  2. Step 2: Convert to fraction form
    309.89/427.65 = 199.43/x
  3. Step 3: Cross multiply
    309.89x = 427.65 × 199.43
  4. Step 4: Simplify right side
    309.89x = 85,286.24
  5. Step 5: Solve for x
    x = 85,286.24/309.89
  6. Step 6: Final answer
    x = 275.21

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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.