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Finding the Fourth Proportional to 685.70, 1,028.94 and 290.35

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Solution

The fourth proportional to 685.70, 1,028.94 and 290.35 is: 435.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.70 : 1,028.94 = 290.35 : x
  2. Step 2: Convert to fraction form
    685.70/1,028.94 = 290.35/x
  3. Step 3: Cross multiply
    685.70x = 1,028.94 × 290.35
  4. Step 4: Simplify right side
    685.70x = 298,750.16
  5. Step 5: Solve for x
    x = 298,750.16/685.70
  6. Step 6: Final answer
    x = 435.69

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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.