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Finding the Fourth Proportional to 309.68, 427.32 and 199.20

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Solution

The fourth proportional to 309.68, 427.32 and 199.20 is: 274.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.68 : 427.32 = 199.20 : x
  2. Step 2: Convert to fraction form
    309.68/427.32 = 199.20/x
  3. Step 3: Cross multiply
    309.68x = 427.32 × 199.20
  4. Step 4: Simplify right side
    309.68x = 85,122.14
  5. Step 5: Solve for x
    x = 85,122.14/309.68
  6. Step 6: Final answer
    x = 274.87

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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.