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Finding the Fourth Proportional to 858.89, 1,290.77 and 664.49

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Solution

The fourth proportional to 858.89, 1,290.77 and 664.49 is: 998.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.89 : 1,290.77 = 664.49 : x
  2. Step 2: Convert to fraction form
    858.89/1,290.77 = 664.49/x
  3. Step 3: Cross multiply
    858.89x = 1,290.77 × 664.49
  4. Step 4: Simplify right side
    858.89x = 857,693.98
  5. Step 5: Solve for x
    x = 857,693.98/858.89
  6. Step 6: Final answer
    x = 998.61

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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.