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Finding the Fourth Proportional to 320.81, 480.74 and 255.45

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Solution

The fourth proportional to 320.81, 480.74 and 255.45 is: 382.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.81 : 480.74 = 255.45 : x
  2. Step 2: Convert to fraction form
    320.81/480.74 = 255.45/x
  3. Step 3: Cross multiply
    320.81x = 480.74 × 255.45
  4. Step 4: Simplify right side
    320.81x = 122,805.56
  5. Step 5: Solve for x
    x = 122,805.56/320.81
  6. Step 6: Final answer
    x = 382.80

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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.