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Finding the Fourth Proportional to 685.50, 1,028.40 and 274.56

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Solution

The fourth proportional to 685.50, 1,028.40 and 274.56 is: 411.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.50 : 1,028.40 = 274.56 : x
  2. Step 2: Convert to fraction form
    685.50/1,028.40 = 274.56/x
  3. Step 3: Cross multiply
    685.50x = 1,028.40 × 274.56
  4. Step 4: Simplify right side
    685.50x = 282,357.50
  5. Step 5: Solve for x
    x = 282,357.50/685.50
  6. Step 6: Final answer
    x = 411.90

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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.