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Finding the Fourth Proportional to 685.26, 1,028.22 and 319.99

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Solution

The fourth proportional to 685.26, 1,028.22 and 319.99 is: 480.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.26 : 1,028.22 = 319.99 : x
  2. Step 2: Convert to fraction form
    685.26/1,028.22 = 319.99/x
  3. Step 3: Cross multiply
    685.26x = 1,028.22 × 319.99
  4. Step 4: Simplify right side
    685.26x = 329,020.12
  5. Step 5: Solve for x
    x = 329,020.12/685.26
  6. Step 6: Final answer
    x = 480.14

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.