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Finding the Fourth Proportional to 643.32, 965.16 and 210.78

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Solution

The fourth proportional to 643.32, 965.16 and 210.78 is: 316.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.32 : 965.16 = 210.78 : x
  2. Step 2: Convert to fraction form
    643.32/965.16 = 210.78/x
  3. Step 3: Cross multiply
    643.32x = 965.16 × 210.78
  4. Step 4: Simplify right side
    643.32x = 203,436.42
  5. Step 5: Solve for x
    x = 203,436.42/643.32
  6. Step 6: Final answer
    x = 316.23

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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.