Question 1

An online poll asked people what their main source of news was: newspapers,television,internet,or radio.Here are the results: $$\begin{array} { l | l } 
\text { Response } & \text { Number } \
\hline \text { Newspapers } & 241 \
\text { Television } & 398 \
\text { Internet } & 105 \
\text { Radio } & 164 \
\hline \text { Total } & 908
\end{array}$$ If we select a person at random from this sample of 908 people,what is the probability that the person responded "Internet" or "Radio"?

Accepted Answer

A) 0.116 
B) 0.704 
C) 0.296 
D) 0.181 
E) 269

Question 2

The table shows the political affiliation of voters in one city and their positions on raising taxes. Raising Taxes $$\begin{array} { l | c | c } 
& \text { Favor } & \text { Oppose } \
\hline \text { NDP } & 0.09 & 0.27 \
\text { Conservative } & 0.23 & 0.17 \
\text { Other } & 0.15 & 0.09
\end{array}$$ What is the probability that a randomly picked person votes Conservative and opposes raising taxes?

Accepted Answer

A) 0.321 
B) 0.400 
C) 0.530 
D) 0.425 
E) 0.170

Question 3

The plastic arrow on a spinner for a child's game stops rotating to point at one of four colours that will determine what happens next.Determine whether the following probability assignment is legitimate. Probability of ... $$\begin{array} { c | l | c | c } 
\text { Red } & \text { Yellow } & \text { Green } & \text { Blue } \
\hline 0.40 & 0.10 & - 0.90 & 1.40
\end{array}$$

Accepted Answer

A) Legitimate 
B) Not legitimate

Question 4

The probability that a student at a certain college is male is 0.47.The probability that a student at that college has a job off campus is 0.22.The probability that a student at the college is male and has a job off campus is 0.12.If a student is chosen at random from the college,what is the probability that the student is male or has an off campus job?

Accepted Answer

A) 0.57 
B) 0.00 
C) 0.81 
D) 0.69 
E) 0.45

Question 5

A random spinner can land on red,green,blue,or yellow.If on the first three spins it lands once each on red,green,and yellow,is it more likely to land on blue on the fourth spin?

Accepted Answer

A) Yes,because every color is equally likely to occur. 
B) Yes,because the Probability Assignment Rule dictates that all outcomes should occur. 
C) No,because the spins are disjoint events. 
D) Yes,because the spinner shows randomness,not chaos. 
E) No,because knowing one outcome will not affect the next.

Question 6

A telemarketer is almost through with her entire shift,and she has not made a single sale.Her manager says that she has a good chance of making a sale on her last few phone calls because she is due.Is her manager right?

Accepted Answer

A) No,because the Probability Assignment Rule applies in the long-run,not in the short-run. 
B) Yes,because the Law of Averages is valid for independent events. 
C) No,because there is no Law of Large Numbers for independent events. 
D) Yes,because the Law of Large Numbers is valid for independent events. 
E) No,because there is no Law of Averages for independent events.

Question 7

In a business class,40% of the students have never taken a statistics class,15% have taken only one semester of statistics,and the rest have taken two or more semesters of statistics.The professor randomly assigns students to groups of three to work on a project for the course.What is the probability that the first group mate you meet has studied two or more semesters of statistics?

Accepted Answer

A) 0.55 
B) 0.85 
C) 0.15 
D) 0.45 
E) 0.60

Question 8

The contingency table below provides a joint frequency distribution for a random sample of patients at a hospital classified by blood type and sex. Blood Type $$\begin{array} { | l | c | c | c | c | c | } 
\hline \text { Sex } & \text { O } & \text { A } & \text { B } & \text { AB } & \text { Total } \
\hline \text { F } & 105 & 85 & 24 & 11 & 225 \
\hline M & 72 & 74 & 15 & 4 & 165 \
\hline \text { Total } & 177 & 159 & 39 & 15 & 390 \
\hline
\end{array}$$ If a person is selected at random from the sample,find the probability that the person has blood type A or is female.

Accepted Answer

A) 0.985 
B) 0.767 
C) 0.378 
D) 0.535 
E) 0.218

Question 9

In a survey of women who were asked to name their favorite colour,15% said blue,15% said red,18% said green,14% said yellow,and 12% said black.If you pick a survey participant at random,what is the probability that her favorite colour is not red?

Accepted Answer

A) 0.75 
B) 0.85 
C) 0.15 
D) 0.50 
E) 0.59

Exam 12: From Randomness to Probability

A random spinner can land on red,green,blue,or yellow.If on the first three spins it lands once each on red,green,and yellow,is it more likely to land on blue on the fourth spin?

A telemarketer is almost through with her entire shift,and she has not made a single sale.Her manager says that she has a good chance of making a sale on her last few phone calls because she is due.Is her manager right?

In a survey of women who were asked to name their favorite colour,15% said blue,15% said red,18% said green,14% said yellow,and 12% said black.If you pick a survey participant at random,what is the probability that her favorite colour is not red?