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Finding the Fourth Proportional to 685.30, 1,028.55 and 274.72

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Solution

The fourth proportional to 685.30, 1,028.55 and 274.72 is: 412.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.30 : 1,028.55 = 274.72 : x
  2. Step 2: Convert to fraction form
    685.30/1,028.55 = 274.72/x
  3. Step 3: Cross multiply
    685.30x = 1,028.55 × 274.72
  4. Step 4: Simplify right side
    685.30x = 282,563.26
  5. Step 5: Solve for x
    x = 282,563.26/685.30
  6. Step 6: Final answer
    x = 412.32

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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.