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Finding the Fourth Proportional to 685.85, 1,028.77 and 623.21

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Solution

The fourth proportional to 685.85, 1,028.77 and 623.21 is: 934.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.85 : 1,028.77 = 623.21 : x
  2. Step 2: Convert to fraction form
    685.85/1,028.77 = 623.21/x
  3. Step 3: Cross multiply
    685.85x = 1,028.77 × 623.21
  4. Step 4: Simplify right side
    685.85x = 641,133.05
  5. Step 5: Solve for x
    x = 641,133.05/685.85
  6. Step 6: Final answer
    x = 934.81

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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.