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Finding the Fourth Proportional to 685.69, 1,028.53 and 172.69

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Solution

The fourth proportional to 685.69, 1,028.53 and 172.69 is: 259.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.69 : 1,028.53 = 172.69 : x
  2. Step 2: Convert to fraction form
    685.69/1,028.53 = 172.69/x
  3. Step 3: Cross multiply
    685.69x = 1,028.53 × 172.69
  4. Step 4: Simplify right side
    685.69x = 177,614.49
  5. Step 5: Solve for x
    x = 177,614.49/685.69
  6. Step 6: Final answer
    x = 259.03

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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.