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Finding the Fourth Proportional to 255.20, 380.31 and 247.78

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Solution

The fourth proportional to 255.20, 380.31 and 247.78 is: 369.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    255.20 : 380.31 = 247.78 : x
  2. Step 2: Convert to fraction form
    255.20/380.31 = 247.78/x
  3. Step 3: Cross multiply
    255.20x = 380.31 × 247.78
  4. Step 4: Simplify right side
    255.20x = 94,232.01
  5. Step 5: Solve for x
    x = 94,232.01/255.20
  6. Step 6: Final answer
    x = 369.25

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.