<PRE><B>Question 207750</B>
Section 4.1 Probability Distribution
1.   Decide whether the random variable is discrete or continuous.
(References: example 1 page 195, end of section exercises  13 – 20 page 201)  (1 points per each part)

a.	The cost of a randomly selected apple: discrete
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b.	The height of randomly selected Statistics student: continuous
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c.	The number of books in the local college library: discrete
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d.	The braking time of a motorcycle: discrete
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e.	The number of cell phone call between Bagdad and Ft Bragg, NC on Christmas day in the current year: discrete
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2.  Decide whether the distribution is a probability distribution. If it is not a probability distribution, identify the property that is not satisfied. (References: example 3 and 4   page 197, end of section exercises 25 - 28 page 202 - 203)  
 	
x	P(x)
0	0.49
1	0.05
2	0.32
3	0.07
4	0.07
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It is a probability distribution
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3.	A batch of 4 computers and the probabilities associated with the defectives in the group. Complete the table shown and find the mean, variance, and standard deviation for the distribution. Round a – c to 2 decimal places.
(References: example 5 and 6 page 198 - 199, end of section exercises 29 - 34 page 203)  

x P(x).. x &amp;#61655; P(x)... x - &amp;#61549; (x - &amp;#61549;)2 P(x) &amp;#61655; (x - &amp;#61549;)2
0 0.34.......0..........?...........?........? 
1 0.17 
2 0.26 
3 0.21 
4 0.02 
&amp;#61669; x &amp;#61655; P(x) = &amp;#61669; P(x) &amp;#61655; (x - &amp;#61549;)2 = 
(5 points for table)
a. Mean &amp;#61549; 
(2 points)
= 1.596 
b. Variance &amp;#61555;2 
(2 points)
=1.204784 




Section 4.2: Binomial Probability

Find the indicated binomial probabilities. Round to the nearest 3 decimal places. (References: example 6 page 212, end of section exercises 15 - 24 page 216 - 217)  For part d and e: (References: example 8 page 214)

4.	The probability that a pumpkin seed will germinate is 70%. A gardener plants in batches of 12.  (1 points each)
a.	What is the probability that exactly 10 seeds will germinate?
P(x=10) = 12C10(0.7)^10(0.3)^2 = 66(0.02825)(0.09) = 0.1678
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	     b.   What is the probability that 10 or more will germinate?
P(10&lt;=x&lt;=12) = 0.2528
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	     c.   What is the probability that all seeds will germinate?
P(x=12) = 0.7^12 = 0.0138..
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               d.   Find the mean &amp;#61549;
Ans: ?
     
     e.  Find the variance &amp;#61555;2 
Ans: ?
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5.	A True-False test has 20 questions with each having 2 possible answers with one correct. Assume a student answers every question. 
a. What is the probability of getting exactly 9 correct answers?
P(x=9) = 20C9(1/2)^9(1/2)^11 = 167960(1/2^20) = 0.1602
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b. What is the probability of getting less than 6 correct answers?
P(0&lt;= x &lt;= 5) = 0.027
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Cheers,
Stan H.	


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