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Finding the Fourth Proportional to 309.63, 427.09 and 185.21

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Solution

The fourth proportional to 309.63, 427.09 and 185.21 is: 255.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.63 : 427.09 = 185.21 : x
  2. Step 2: Convert to fraction form
    309.63/427.09 = 185.21/x
  3. Step 3: Cross multiply
    309.63x = 427.09 × 185.21
  4. Step 4: Simplify right side
    309.63x = 79,100.41
  5. Step 5: Solve for x
    x = 79,100.41/309.63
  6. Step 6: Final answer
    x = 255.47

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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.