PSTAT 10 UCSB UPDATED ACTUAL
Exam Questions and CORRECT Answers
Binomial Random Variable - CORRECT ANSWER - Trials must be independent
Success probability of each trial to remain the same
Fixed number of trials\
2 possible outcomes
cumsum(c(1,5)) - CORRECT ANSWER -16
What code will generate 200 random variates of a standard normal distribution? - CORRECT
ANSWER - rvariates<-rnorm(n=200,mean=0,sd=1)
It has been estimated that 30% of frozen chicken contains enough salmonella bacteria to cause
illness if improperly cooked. A consumer purchases 12 frozen chickens. How would you find the
probability the consumer will have more than 6 contaminated chickens? - CORRECT
ANSWER - Find the probability that X>6 in a binomial distribution with n=12 and p=0.30
Suppose there are 12 multiple choice questions. Each question has 5 possible answers and only
one of them is correct. What is the probability of having four or fewer correct answers if a
student attempts to answer every question at random? - CORRECT ANSWER - pbinom(4,
size=12, prob=0.2)
dbinom(k, size, prob) - CORRECT ANSWER - returns the probability of getting exactly k
successes in size trials, each with a probability of success prob.
pbinom(k, size, prob) - CORRECT ANSWER - returns the probability of getting k or
fewer successes in size trials, each with a probability of success prob.
Which of the following is NOT true regarding a binomial experiment? - CORRECT
ANSWER - All the trials be independent
, -number of trials is fixed
-trials can be a success or a failure only
-The probability of success varies for each trial
What is the total area under the standard normal distribution curve? - CORRECT
ANSWER -1
Suppose that the area under the normal curve X - N(50,4) to the left of some unknown x-value is
0.95. Which code will return the value of x? - CORRECT ANSWER -
qnorm(0.95,mean=50,sd=4)
The number of network errors experienced in a day on a local area network (LAN) is 2.4 The
probability than in any given day two or more networks errors will occur is given by -
CORRECT ANSWER - 1-(ppois(1,lambda=2.4))
data<-data.frame(x=c(1,2,3), y=c(5,NA,8) - CORRECT ANSWER - na.omit(data)
#removes values
By obsersavation, I think that a coffee machine fills cups by amounts that are uniformly
distributed. Specifically if selected 12 oz coffee, the machine dispense between 10 and 13 oz,
following a uniform , what is the probability that my choice of a 12 oz coffee wil actually be
between 10oz and 12oz. - CORRECT ANSWER - 2/3
what's not part of the relational model? - CORRECT ANSWER - Security
Which of the following provides the ability to query information from the database and to insert
tuples into , delete tuples from, and modify types in the database? - CORRECT
ANSWER - DML
A relational database designer constructed a database with each relation having a primary key,
where the values of the attributes of that primary key are required to be not null. Which
Exam Questions and CORRECT Answers
Binomial Random Variable - CORRECT ANSWER - Trials must be independent
Success probability of each trial to remain the same
Fixed number of trials\
2 possible outcomes
cumsum(c(1,5)) - CORRECT ANSWER -16
What code will generate 200 random variates of a standard normal distribution? - CORRECT
ANSWER - rvariates<-rnorm(n=200,mean=0,sd=1)
It has been estimated that 30% of frozen chicken contains enough salmonella bacteria to cause
illness if improperly cooked. A consumer purchases 12 frozen chickens. How would you find the
probability the consumer will have more than 6 contaminated chickens? - CORRECT
ANSWER - Find the probability that X>6 in a binomial distribution with n=12 and p=0.30
Suppose there are 12 multiple choice questions. Each question has 5 possible answers and only
one of them is correct. What is the probability of having four or fewer correct answers if a
student attempts to answer every question at random? - CORRECT ANSWER - pbinom(4,
size=12, prob=0.2)
dbinom(k, size, prob) - CORRECT ANSWER - returns the probability of getting exactly k
successes in size trials, each with a probability of success prob.
pbinom(k, size, prob) - CORRECT ANSWER - returns the probability of getting k or
fewer successes in size trials, each with a probability of success prob.
Which of the following is NOT true regarding a binomial experiment? - CORRECT
ANSWER - All the trials be independent
, -number of trials is fixed
-trials can be a success or a failure only
-The probability of success varies for each trial
What is the total area under the standard normal distribution curve? - CORRECT
ANSWER -1
Suppose that the area under the normal curve X - N(50,4) to the left of some unknown x-value is
0.95. Which code will return the value of x? - CORRECT ANSWER -
qnorm(0.95,mean=50,sd=4)
The number of network errors experienced in a day on a local area network (LAN) is 2.4 The
probability than in any given day two or more networks errors will occur is given by -
CORRECT ANSWER - 1-(ppois(1,lambda=2.4))
data<-data.frame(x=c(1,2,3), y=c(5,NA,8) - CORRECT ANSWER - na.omit(data)
#removes values
By obsersavation, I think that a coffee machine fills cups by amounts that are uniformly
distributed. Specifically if selected 12 oz coffee, the machine dispense between 10 and 13 oz,
following a uniform , what is the probability that my choice of a 12 oz coffee wil actually be
between 10oz and 12oz. - CORRECT ANSWER - 2/3
what's not part of the relational model? - CORRECT ANSWER - Security
Which of the following provides the ability to query information from the database and to insert
tuples into , delete tuples from, and modify types in the database? - CORRECT
ANSWER - DML
A relational database designer constructed a database with each relation having a primary key,
where the values of the attributes of that primary key are required to be not null. Which
