Question

(1 point) A customs agent discovers 23 identically looking packets of white power in a traveler's suitcase. Unknown to the customs officer, 17 of these packets contain cocaine, the rest do not contain cocaine.

The customs officer is to randomly pick 4 packets and test each one. A random variable ?X is to count the number of tested packets that test positive for cocaine.

(a) Finish the probability distribution of ?X below. Use four decimals in each of your entries.

?X	0	1	2	3	4
?(?=?)P(X=x)	equation editor Equation Editor	equation editor Equation Editor	equation editor Equation Editor	equation editor Equation Editor	equation editor Equation Editor

(b) From the distribution you found in part (a), what can you say about the distribution of ?X?

The distribution of ?X is  ? symmetrical skewed to the right skewed to the left .


(c) How many of the 4 packets do you expect be to test positive for cocaine? Provide the standard deviation as well.

?(?)=E(X)=

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(use two decimals)

??(?)=SD(X)=

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(use two decimals)

Answer 1