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Unformatted text preview: Quiz #2 MA 223, Engineering Statistics
Spring 2008; 10 points possible
Sections 1.4 — 2.2 Date: Friday, March 14 NAME: 233/ CM Box #: You may NOT use Minitab or Maple on this quiz. 1. [+1 each  +0.5 for correctly shading & +0.5 for correct answer from table] Assume the variable 2
follows a standard normal distribution; that is, assume 2 is normally distributed with u = 0 and a = 1.
Shade the region corresponding to the proportion of observations satisfying the stated criteria. Then use the z—table in the front of the book to ﬁnd the proportion. (a) p(Z>—1.16)=ﬂ
3%? 419‘) r @722 MA} (b) p(z < 0.74) = “jg/$357!; (c) p(—1.16 < z < 0.74) = Q : Macaw}  PfﬁHé‘) .7404 * .{ZEC’ 2. [+2 pts each] Suppose the amount of time (min) which it takes a Rose Hulman student to donate a pint of
blood is known to be normally distributed with u = 16 and a = 3. (Part (b) is on the next page.) (a) What proportion of Rose students are able to donate a pint of blood in less than 20 minutes? (b) What donation time is exceeded by only 1% of Rose students? v K a A A i
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For a binomial distribution with number of trials 11 and proportion of successes n, the mass function for the
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p(x) = 11"(1 — 7t)""‘ for X: 0,1, 2,3, n.
. n __ n! _
Note. (x) — x!(n_x)!, where 0! — 1.
3. [+2 pts] Suppose it is known that 65% of all Rose students have blood type A. If the blood donated by
10 Rose students is tested, what proportion of the time would you expect there to be exactly 8 students with
blood type A?
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E W43“ 7mm in” ‘5 \V ,,,,,,,,,,,,,,,,,,,,,,,,,, MWMMWW‘ 4. [+1 pt] The number of students donating blood was recorded every 30 minutes between 11:00 am. and 5:00 pm. The data follows: What is the median of this data set? Oﬁbgwgb : '3) E) 2 S 1 (I; 5; L9; :7; m“: 1%
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This note was uploaded on 04/24/2008 for the course MA 223 taught by Professor Devasher during the Spring '08 term at RoseHulman.
 Spring '08
 DeVasher
 Statistics

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