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Finding the Fourth Proportional to 643.71, 965.63 and 210.95

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Solution

The fourth proportional to 643.71, 965.63 and 210.95 is: 316.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.71 : 965.63 = 210.95 : x
  2. Step 2: Convert to fraction form
    643.71/965.63 = 210.95/x
  3. Step 3: Cross multiply
    643.71x = 965.63 × 210.95
  4. Step 4: Simplify right side
    643.71x = 203,695.35
  5. Step 5: Solve for x
    x = 203,695.35/643.71
  6. Step 6: Final answer
    x = 316.44

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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.