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Finding the Fourth Proportional to 685.84, 1,028.20 and 274.88

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Solution

The fourth proportional to 685.84, 1,028.20 and 274.88 is: 412.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.84 : 1,028.20 = 274.88 : x
  2. Step 2: Convert to fraction form
    685.84/1,028.20 = 274.88/x
  3. Step 3: Cross multiply
    685.84x = 1,028.20 × 274.88
  4. Step 4: Simplify right side
    685.84x = 282,631.62
  5. Step 5: Solve for x
    x = 282,631.62/685.84
  6. Step 6: Final answer
    x = 412.10

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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.