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Finding the Fourth Proportional to 421.80, 582.09 and 255.99

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Solution

The fourth proportional to 421.80, 582.09 and 255.99 is: 353.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.80 : 582.09 = 255.99 : x
  2. Step 2: Convert to fraction form
    421.80/582.09 = 255.99/x
  3. Step 3: Cross multiply
    421.80x = 582.09 × 255.99
  4. Step 4: Simplify right side
    421.80x = 149,009.22
  5. Step 5: Solve for x
    x = 149,009.22/421.80
  6. Step 6: Final answer
    x = 353.27

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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.