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Finding the Fourth Proportional to 309.72, 427.04 and 287.84

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Solution

The fourth proportional to 309.72, 427.04 and 287.84 is: 396.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.72 : 427.04 = 287.84 : x
  2. Step 2: Convert to fraction form
    309.72/427.04 = 287.84/x
  3. Step 3: Cross multiply
    309.72x = 427.04 × 287.84
  4. Step 4: Simplify right side
    309.72x = 122,919.19
  5. Step 5: Solve for x
    x = 122,919.19/309.72
  6. Step 6: Final answer
    x = 396.87

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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.