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Finding the Fourth Proportional to 643.61, 965.18 and 210.67

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Solution

The fourth proportional to 643.61, 965.18 and 210.67 is: 315.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.61 : 965.18 = 210.67 : x
  2. Step 2: Convert to fraction form
    643.61/965.18 = 210.67/x
  3. Step 3: Cross multiply
    643.61x = 965.18 × 210.67
  4. Step 4: Simplify right side
    643.61x = 203,332.58
  5. Step 5: Solve for x
    x = 203,332.58/643.61
  6. Step 6: Final answer
    x = 315.92

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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.