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Finding the Fourth Proportional to 399.53, 550.80 and 310.74

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Solution

The fourth proportional to 399.53, 550.80 and 310.74 is: 428.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.53 : 550.80 = 310.74 : x
  2. Step 2: Convert to fraction form
    399.53/550.80 = 310.74/x
  3. Step 3: Cross multiply
    399.53x = 550.80 × 310.74
  4. Step 4: Simplify right side
    399.53x = 171,153.53
  5. Step 5: Solve for x
    x = 171,153.53/399.53
  6. Step 6: Final answer
    x = 428.38

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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.