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Finding the Fourth Proportional to 643.69, 965.67 and 210.81

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Solution

The fourth proportional to 643.69, 965.67 and 210.81 is: 316.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.69 : 965.67 = 210.81 : x
  2. Step 2: Convert to fraction form
    643.69/965.67 = 210.81/x
  3. Step 3: Cross multiply
    643.69x = 965.67 × 210.81
  4. Step 4: Simplify right side
    643.69x = 203,572.89
  5. Step 5: Solve for x
    x = 203,572.89/643.69
  6. Step 6: Final answer
    x = 316.26

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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.