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Finding the Fourth Proportional to 399.24, 550.59 and 310.74

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Solution

The fourth proportional to 399.24, 550.59 and 310.74 is: 428.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.24 : 550.59 = 310.74 : x
  2. Step 2: Convert to fraction form
    399.24/550.59 = 310.74/x
  3. Step 3: Cross multiply
    399.24x = 550.59 × 310.74
  4. Step 4: Simplify right side
    399.24x = 171,090.34
  5. Step 5: Solve for x
    x = 171,090.34/399.24
  6. Step 6: Final answer
    x = 428.54

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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.