Quiz #3 Solutions
1 H0 : p = 0.5 and H1 : p = 0.5. This is a two sided test. Sample
proportion p = 0.7, sample size n = 100.
2 Test statistic Z =
pp
p(1p)
n
=
0.70.5
0.5(10.5)
100
3 If |Z | > Z = Z0.025 = 1.96 we reject H0
2
1
Quiz #1
Q1 Given that events A and B are such that P (A) = 0.3, P (B ) = 0.5 and
P (A B ) = 0.65
(a) Find P (A B )
(b) Are events A and B independent? Why?
Q2 Given pmf p(x) = cx for x = 0, 1, 2
(a) Find c
(b) Find E (X )
(c) Find V ar(X )
Solutions
Q1 Gi
Homework #5 Due Friday 2/27
Instructions:
For this assignment use the data from exercise 14 (page 23) on shower ow
rates. The data can also be obtained from the class website. Submit a
type written assignment of 1 or 2 pages with all your answers in bold
Homework #4 Due Friday 02/13
A: From chapter 4 do problems: 6; 11 (a),(b),(c),(d),(e); 18; 26; 27
(a),(b),(c); 29; 30
B: From chapter 5 do problems: 2, 12
C: Using p(x, y ) given in no. 1 of chapter 5 nd E(X), E(Y), E(XY),
V(X), V(Y), Are X and Y independ
Homework #3 Solutions
You can use tables to get F (x) = P (X x)
#70
(a) X Hyper(N, M, n) with N = 50, M = 15 and n = 10 so
35
(15)(10 )
p(x) = x 50 x
(10)
(b) When N is large compared to n we can have p = M/M = 15/50 = 0.3.
Thus X B (10, 0.3) (approx.)
(c
Final Exam Review
Important note:
The Final Exam is on Monday May 3rd, 2004 at 08:00 am in 216 Thomas building.
The exam will be one hour long. The nal exam is not an open book exam!
Youre however allowed to bring 3 sheets of summarized notes. You should
Exam 2 Solutions
1. IQR=Q3-Q1=11.35-9.1=2.25
Q1-1.5IQR=9.1-1.5(2.25)=5.725
Q3+1.5IQR=11.35+1.5(2.25)=14.725
Outliers are values less than 5.725 or greater than 14.725. So 4.3, 15.6
and 16.0 are outliers.
2. p = 0.7, n = 100
(a) H0 : p = 0.8 and H1 : p > 0
1. [10 points] A student has 3 options to get to his stat 401 class; walking
(W), cycling (C) or taking the bus (B) with probabilities P (W ) = 0.2,
P (C ) = 0.5 and P (B ) = 0.3. For the 3 options he has, the student arrives late (L) for class with proba