Question 815320
1. A ball is drawn at random from a box containing 6 red balls, 4 white balls, and 5 blue balls. 
Determine the probability that the ball drawn is

(a) red. 
<pre>
6 ways out of 15 = {{{6/15}}} = {{{2/5}}}
</pre>
(b) white, 
<pre>
4 ways out of 15 = {{{4/15}}} 
</pre>
(c) not red. 
<pre>
That's the complement of (a), so it's 1 - {{{2/5}}} = {{{3/5}}}
</pre>
(d) red or white.
<pre>
10 ways out of 15 = {{{10/15}}} = {{{2/3}}}

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</pre>
5. The mean weight of 500 male students at a certain college is 151 pounds (lb), and the standard deviation  is 15 lb. Assuming that the weights are normally distributed, find the probability of students weight  
(a) between 121 and 155 lb
<pre>
TI-83 or 84 calculator under 2ND VARS

normalcdf(121,155,151,15)

.58238697
</pre>
(b) more than 185 lb.
<pre>

normalcdf(185,99999999,151,15)

.0117052622
</pre>
(c) if 4% of the students are overweight, what is the minimum weight to  classify student as over weight?
<pre>
invNorm(1-.04,151,15)

177.2602911

Edwin</pre>