Question 887733
The number of defective pieces in a sample of 20 bulbs are 
Number of 
defective 
pieces 0 1 2 3 4 5 
Frequency 8 10 12 3 5 2 

The average number of defective piece per sample is ?
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[0*8+1*10+2*12 + 3*3 + 4*5 + 5*2]/[8+10+12+3+5+2] = 73/40 = 1.825
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Cheers,
Stan H.
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