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Finding the Fourth Proportional to 688.86, 1,033.73 and 643.30

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Solution

The fourth proportional to 688.86, 1,033.73 and 643.30 is: 965.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.86 : 1,033.73 = 643.30 : x
  2. Step 2: Convert to fraction form
    688.86/1,033.73 = 643.30/x
  3. Step 3: Cross multiply
    688.86x = 1,033.73 × 643.30
  4. Step 4: Simplify right side
    688.86x = 664,998.51
  5. Step 5: Solve for x
    x = 664,998.51/688.86
  6. Step 6: Final answer
    x = 965.36

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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.