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Finding the Fourth Proportional to 399.08, 550.71 and 310.65

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Solution

The fourth proportional to 399.08, 550.71 and 310.65 is: 428.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.08 : 550.71 = 310.65 : x
  2. Step 2: Convert to fraction form
    399.08/550.71 = 310.65/x
  3. Step 3: Cross multiply
    399.08x = 550.71 × 310.65
  4. Step 4: Simplify right side
    399.08x = 171,078.06
  5. Step 5: Solve for x
    x = 171,078.06/399.08
  6. Step 6: Final answer
    x = 428.69

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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.