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Finding the Fourth Proportional to 685.16, 1,028.55 and 300.68

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Solution

The fourth proportional to 685.16, 1,028.55 and 300.68 is: 451.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.16 : 1,028.55 = 300.68 : x
  2. Step 2: Convert to fraction form
    685.16/1,028.55 = 300.68/x
  3. Step 3: Cross multiply
    685.16x = 1,028.55 × 300.68
  4. Step 4: Simplify right side
    685.16x = 309,264.41
  5. Step 5: Solve for x
    x = 309,264.41/685.16
  6. Step 6: Final answer
    x = 451.38

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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.