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Finding the Fourth Proportional to 685.51, 1,028.75 and 274.75

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Solution

The fourth proportional to 685.51, 1,028.75 and 274.75 is: 412.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.51 : 1,028.75 = 274.75 : x
  2. Step 2: Convert to fraction form
    685.51/1,028.75 = 274.75/x
  3. Step 3: Cross multiply
    685.51x = 1,028.75 × 274.75
  4. Step 4: Simplify right side
    685.51x = 282,645.12
  5. Step 5: Solve for x
    x = 282,645.12/685.51
  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.