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Finding the Fourth Proportional to 685.78, 1,028.81 and 377.47

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Solution

The fourth proportional to 685.78, 1,028.81 and 377.47 is: 566.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.78 : 1,028.81 = 377.47 : x
  2. Step 2: Convert to fraction form
    685.78/1,028.81 = 377.47/x
  3. Step 3: Cross multiply
    685.78x = 1,028.81 × 377.47
  4. Step 4: Simplify right side
    685.78x = 388,343.28
  5. Step 5: Solve for x
    x = 388,343.28/685.78
  6. Step 6: Final answer
    x = 566.28

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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.