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Finding the Fourth Proportional to 398.42, 550.09 and 305.00

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Solution

The fourth proportional to 398.42, 550.09 and 305.00 is: 421.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.42 : 550.09 = 305.00 : x
  2. Step 2: Convert to fraction form
    398.42/550.09 = 305.00/x
  3. Step 3: Cross multiply
    398.42x = 550.09 × 305.00
  4. Step 4: Simplify right side
    398.42x = 167,777.14
  5. Step 5: Solve for x
    x = 167,777.14/398.42
  6. Step 6: Final answer
    x = 421.11

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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.