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Finding the Fourth Proportional to 685.71, 1,028.79 and 274.77

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Solution

The fourth proportional to 685.71, 1,028.79 and 274.77 is: 412.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.71 : 1,028.79 = 274.77 : x
  2. Step 2: Convert to fraction form
    685.71/1,028.79 = 274.77/x
  3. Step 3: Cross multiply
    685.71x = 1,028.79 × 274.77
  4. Step 4: Simplify right side
    685.71x = 282,680.63
  5. Step 5: Solve for x
    x = 282,680.63/685.71
  6. Step 6: Final answer
    x = 412.25

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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.