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Finding the Fourth Proportional to 684.84, 1,020.60 and 664.02

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Solution

The fourth proportional to 684.84, 1,020.60 and 664.02 is: 989.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.84 : 1,020.60 = 664.02 : x
  2. Step 2: Convert to fraction form
    684.84/1,020.60 = 664.02/x
  3. Step 3: Cross multiply
    684.84x = 1,020.60 × 664.02
  4. Step 4: Simplify right side
    684.84x = 677,698.81
  5. Step 5: Solve for x
    x = 677,698.81/684.84
  6. Step 6: Final answer
    x = 989.57

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.