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Finding the Fourth Proportional to 621.05, 931.37 and 255.78

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Solution

The fourth proportional to 621.05, 931.37 and 255.78 is: 383.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.05 : 931.37 = 255.78 : x
  2. Step 2: Convert to fraction form
    621.05/931.37 = 255.78/x
  3. Step 3: Cross multiply
    621.05x = 931.37 × 255.78
  4. Step 4: Simplify right side
    621.05x = 238,224.54
  5. Step 5: Solve for x
    x = 238,224.54/621.05
  6. Step 6: Final answer
    x = 383.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.