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Finding the Fourth Proportional to 309.91, 427.67 and 199.39

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Solution

The fourth proportional to 309.91, 427.67 and 199.39 is: 275.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.91 : 427.67 = 199.39 : x
  2. Step 2: Convert to fraction form
    309.91/427.67 = 199.39/x
  3. Step 3: Cross multiply
    309.91x = 427.67 × 199.39
  4. Step 4: Simplify right side
    309.91x = 85,272.12
  5. Step 5: Solve for x
    x = 85,272.12/309.91
  6. Step 6: Final answer
    x = 275.15

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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.