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Finding the Fourth Proportional to 664.75, 990.31 and 634.77

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Solution

The fourth proportional to 664.75, 990.31 and 634.77 is: 945.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.75 : 990.31 = 634.77 : x
  2. Step 2: Convert to fraction form
    664.75/990.31 = 634.77/x
  3. Step 3: Cross multiply
    664.75x = 990.31 × 634.77
  4. Step 4: Simplify right side
    664.75x = 628,616.26
  5. Step 5: Solve for x
    x = 628,616.26/664.75
  6. Step 6: Final answer
    x = 945.64

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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.