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Finding the Fourth Proportional to 643.09, 893.62 and 636.40

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Solution

The fourth proportional to 643.09, 893.62 and 636.40 is: 884.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.09 : 893.62 = 636.40 : x
  2. Step 2: Convert to fraction form
    643.09/893.62 = 636.40/x
  3. Step 3: Cross multiply
    643.09x = 893.62 × 636.40
  4. Step 4: Simplify right side
    643.09x = 568,699.77
  5. Step 5: Solve for x
    x = 568,699.77/643.09
  6. Step 6: Final answer
    x = 884.32

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.