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Finding the Fourth Proportional to 310.99, 428.34 and 279.82

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Solution

The fourth proportional to 310.99, 428.34 and 279.82 is: 385.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.99 : 428.34 = 279.82 : x
  2. Step 2: Convert to fraction form
    310.99/428.34 = 279.82/x
  3. Step 3: Cross multiply
    310.99x = 428.34 × 279.82
  4. Step 4: Simplify right side
    310.99x = 119,858.10
  5. Step 5: Solve for x
    x = 119,858.10/310.99
  6. Step 6: Final answer
    x = 385.41

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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.