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Finding the Fourth Proportional to 643.55, 965.35 and 210.69

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Solution

The fourth proportional to 643.55, 965.35 and 210.69 is: 316.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.55 : 965.35 = 210.69 : x
  2. Step 2: Convert to fraction form
    643.55/965.35 = 210.69/x
  3. Step 3: Cross multiply
    643.55x = 965.35 × 210.69
  4. Step 4: Simplify right side
    643.55x = 203,389.59
  5. Step 5: Solve for x
    x = 203,389.59/643.55
  6. Step 6: Final answer
    x = 316.05

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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.