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Finding the Fourth Proportional to 890.08, 1,221.78 and 789.64

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Solution

The fourth proportional to 890.08, 1,221.78 and 789.64 is: 1,083.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.08 : 1,221.78 = 789.64 : x
  2. Step 2: Convert to fraction form
    890.08/1,221.78 = 789.64/x
  3. Step 3: Cross multiply
    890.08x = 1,221.78 × 789.64
  4. Step 4: Simplify right side
    890.08x = 964,762.41
  5. Step 5: Solve for x
    x = 964,762.41/890.08
  6. Step 6: Final answer
    x = 1,083.91

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.