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Finding the Fourth Proportional to 685.78, 1,028.76 and 274.96

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Solution

The fourth proportional to 685.78, 1,028.76 and 274.96 is: 412.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.78 : 1,028.76 = 274.96 : x
  2. Step 2: Convert to fraction form
    685.78/1,028.76 = 274.96/x
  3. Step 3: Cross multiply
    685.78x = 1,028.76 × 274.96
  4. Step 4: Simplify right side
    685.78x = 282,867.85
  5. Step 5: Solve for x
    x = 282,867.85/685.78
  6. Step 6: Final answer
    x = 412.48

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1.5x scale

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.