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Blackboard Problem Set #10a
1.
Test Z is a standardized test that all high school seniors take. The mean test score for a rand
sample of 30 students who take the test is 75.7. The population standard deviation is 12. A
school counselor hypothesizes tha
10 U
Blackboard Problem Set #10b
1.
Students are randomly assigned into a treatment group and a control group. Members of the
treatment group use method B to learn how to read. Members of the control group follow th
traditional curriculum. After eight wee
Blackboard Problem Set #9b
Test Z is a standardized test that all high school seniors take. The mean test score foi
random sample of 30 students who take the test is 75. The sample standard deviatior
10. Using this data, a 90% confidence interval for the
CH
Blackboard Problem Set #8a
X-y
1.
An SRS of 1000 adults asks if they agree with the statement "I support President
Obama." Suppose that 60% of all US adults would agree if asked this question so th
population parameter P = 0.6. Round the standard devia
Blackboard Problem Set #9a
1.
The mean monthly rent for a random sample of 30 apartments advertised in the local
newspaper is $1200. The population standard deviation is $200. Using this data, aj?
confidence interval for the population mean rent is constr
Blackboard Problem Set #8b
1.
An SRS of 200 adults asks if they agree with the statement "I support President
Obama." Suppose that 50% of all US adults would agree if asked this question so the
population parameter P = 0.50. Round the standard deviation o
Blackboard Problem Set #7a
Remember that the notation we are using is: N(mean, standard deviation).
1.
A repair team is responsible for a stretch of oil pipeline 10 miles long. The distance (in miles) at
which any fracture occurs over the range 0 to 10 mi
CM ^ Rfl-i
et^xzte Kv
\.
(/^
Blackboard Problem Set #6a
Consider the joint probability distribution of X and 7:
0.3
0.1
0.2
0.4
O.Y
What is E(X\y =1) (rounded to four decimal places)?
0/s-
/
Consider the joint probability distribution of X and Y:
x =2
y=l
Blackboard Problem Set #7b
Remember that the notation we are using is: 7V(mean, standard deviation).
1.
A repair team is responsible for a stretch of oil pipeline 40 miles long. The distance (in miles) at
which any fracture occurs over the range 0 to 40 m
Blackboard Problem Set #6b
1.
Melissa has invested 40% of her funds in T-bills and 60% of her funds in stocks. If Xis
the annual return on T-bills and Y the annual return on stocks, the portfolio rate of return
is:
The returns X and Y are random variables
Blackboard Problem Set #5b
1.
The probability distribution of random variable X is given below:
X
1
P(x)
0.8
2
0.2
it=z6) 7 -i = 7
A second random variable is defined as follows: Z = 2X2 - 1 . What is af. (roundec
four decimal places)?
|/0ft) 4 ?(^)= -7,2
Blackboard Problem Set #4b
q-b
1.
2.
Complete Problem #3.83 on page 119. (Round your final answer to four decimal
places. Remember to express your answer as a proportion.)
3.
Complete Problem #3.84 on page 119. (Round your final answer to four decimal
pla
i
2lo
Blackboard Problem Set #5a
1.
The probability distribution of random variable X is given below:
X
P(x)
0.9
0.1
*x
What is o ^ (rounded to four decimal places)?
2.
The probability distribution of random variable X is given below:
X
P(x)
0.9
0.1
A sec
2| :3 Lil/(’7
Blackboard Problem Set #431
1. The voters in a large city are 50% white, 30% black, and 20% Hispanic. Candidate .
Smith wins 60% of the white vote, 20% of the biack vote, and 80%. of the Hispanic vote.
What is the conditional probability tha
Northwestern University
Department of Economics - STAT 210 Introduction to Statistics
Professor: Steen Habermalz - First Midterm Examination - January 29th 2009
INSTRUCTIONS: Please read the whole exam rst. Questions are not ordered by diculty. Answer
all