Zenia Wilson
2/24/13
5.7
Let X denote the crew size of a randomly selected shuttle mission between April 1981 and July
2000.
a. What are the possible values of the random variable X?
cfw_2, 3, 4, 5, 6, 7, 8
b. Use random-variable notation to represent the
Zenia Wilson
3/8/2013
6.89 A variable is normally distributed with mean 6 and standard
deviation 2.
a. Determine and interpret the quartiles of the variable.
Find the x-value having the z-score -0.67
x = + z = 6 + 2(-0.67) = -4.65
the first quartile is -4
Zenia Wilson
4/15/2013
Preliminary data analyses indicate that applying the z-test (Procedure 9.1 on page 380) in Exercises 9.739.78
is reasonable.
9.73 Toxic Mushrooms? Cadmium, a heavy metal, is toxic to animals. Mushrooms, however, are able to absorb
a
Chapter 9
9.1a. 1/6 b. 1/6
9.2 a P ( X 1) =P(1,1)= 1/36 b P(X
6 ) = P(6,6) = 1/36
9.3a P( X = 1) = (1/6) 5 = .0001286 b P( X = 6) = (1/6) 5 = .0001286
9.4 The variance of X is smaller than the variance of X.
9.5 The sampling distribution of the m
Zenia Wilson
2/10/13
4.10 Playing Cards. An ordinary deck of playing cards has 52 cards. There are four suits
spades, hearts, diamonds, and clubswith 13 cards in each suit. Spades and clubs are black;
hearts and diamonds are red. If one of these cards is
CHAPTER 7
Section 7-2
2n
7-1.
E X1 = E
( )
i =1
Xi =
2n
n
1 E 2n
2n i =1
Xi =
1 (2n ) = 2n
E X2 = E
( )
i =1
Xi =
n
1 E n
n i =1
Xi =
1 (n ) = , n
X 1 and X 2 are unbiased estimators of .
The variances are V X 1 =
( )
2
2n
EXAM 3 SPRING 2008
MthSc301 W 7 9/
Name:
Part I: Identiing the correct type of test: Choose the correct type of test from the list below
and write the letter in the space provided by each question. (5 points each)
ne-tailed left z-test for means
Chapter 11
11.1
H 0 : The drug is not safe and effective H 1 : The drug is safe and effective
11.2
H 0 : I will complete the Ph.D. H 1 : I will not be able to complete the Ph.D.
11.3
H 0 : The batter will hit one deep H 1 : The batter will not hi
Chapter 10
10.1 A point estimator is a single value; an interval estimator is a range of values.
10.2 An unbiased estimator of a parameter is an estimator whose expected value equals the parameter.
10.3
10.4
10.5 An unbiased estimator is consiste
CHAPTER 9
Section 9-1
9-1 a)
H 0 : = 25, H1 : 25 H 0 : > 10, H1 : = 10 H 0 : x = 50, H1 : x 50
Yes, because the hypothesis is stated in terms of the parameter of
interest, inequality is in the alternative hypothesis, and the value in the nu
CHAPTER 6
Section 6-1 6-1. Sample average:
n
xi x=
i =1
n
=
592.035 = 74.0044 mm 8
Sample variance:
8
xi = 592.035
i =1 8
xi2 = 43813.18031
i =1
n n
2
xi x -
2 i i =1
s2 =
i =1
n
(592.035)2 43813.18031 -
= 8
n -1 8 -1 0.0001569 = = 0.
CHAPTER 8
Section 8-2 8-1 a.) The confidence level for
x - 2.14 / n x + 2.14 / n is determined by the x - 2.49 / n x + 2.49 / n is determined by the x - 1.85 / n x + 1.85 / n is determined by the
by the value of z0 which is 2.14. From Tab
CHAPTER 4
Section 4-2 4-1. a) P (1 < X ) = e - x dx = ( -e - x )
1
2 .5
1
= e -1 = 0.3679
2 .5 1
b) P (1 < X < 2.5) =
e
1
-x
dx = (-e - x )
= e -1 - e - 2.5 = 0.2858
c) P( X = 3) = e - x dx = 0
3
3
d) P( X < 4) = e - x dx = (-e - x
CHAPTER 2
Section 2-1 2-1. 2-2. Let "a", "b" denote a part above, below the specification S = {aaa, aab, aba, abb, baa, bab, bba, bbb}
Let "e" denote a bit in error Let "o" denote a bit not in error ("o" denotes okay)
eeee, eoee, oeee, ooee, eeeo
CHAPTER 11
Section 11-2 11-1. a)
yi = 0 + 1 xi + i
S xx = 157.42 - 43 = 25.348571 14
572 S xy = 1697.80 - 43(14 ) = -59.057143
2
1 =
S xy S xx
=
-59.057143 = -2.330 25.348571
572 14 43 - ( -2.3298017)( 14 ) = 48.013
0 = y - 1 x = b)
^ ^
CHAPTER 3 Section 3-1 3-1. 3-2 3-3. 3-4 3-5. The range of X is
{0,1,2,.,1000}
, The range of X is {0,12,.,50} , The range of X is {0,12,.,99999} , The range of X is {0,12,3,4,5}
The range of X is 1,2,.,491 . Because 490 parts are conforming, a nonc
Chapter 21
21.1
H 0 : The two population locations are the same H 1 : The location of population 1 is different from the location of population 2
E (T )
T
n1 ( n1 2
E (T )
T
n2
1)
15 (15
15 2
1)
232 .5
n 1n 2 ( n 1
T
n2
1)
(15 )(15 )(15 12
Chapter 6
6.1 a Relative frequency approach b If the conditions today repeat themselves an infinite number of days rain will fall on 10% of the next days.
6.2 a Subjective approach b If all the teams in major league baseball have exactly the same pl