Exam 6: Probability

If P(A)= 0.4 and P(B)= 0.6,then A and B must be mutually exclusive.

Equity Loan Rates A survey of banks estimated the following probabilities for the interest rate being charged on a equity loan based on a 30-year loan,based on past records. Interest Rate 0.0\% 6.5\% 7.0\% 7.5\% >7.5\% Probability 0.20 0.23 0.25 0.28 .04 -If A and B are independent,then P(A|B)= P(A)or P(B|A)= P(B).

Hobby Shop Sales Sales records of a hobby shop showed the following number of radio controlled trucks sold weekly for each of the last 50 weeks. Number of Trucks Sald Number af Weeks 0 20 1 15 2 10 3 4 4 1 -{Hobby Shop Sales Narrative} What approach would you use in determining the probabilities for next week's sales? Assign probabilities to the outcomes.

Equity Loan Rates A survey of banks estimated the following probabilities for the interest rate being charged on a equity loan based on a 30-year loan,based on past records. Interest Rate 0.0\% 6.5\% 7.0\% 7.5\% >7.5\% Probability 0.20 0.23 0.25 0.28 .04 -The probability of the intersection of two events A and B is denoted by P(A and B)and is called the:

Business Majors Suppose 30% of business majors major in accounting.You take a random sample of 3 business majors. -{Business Majors Narrative} What is the chance that exactly one majors in accounting?

Equity Loan Rates A survey of banks estimated the following probabilities for the interest rate being charged on a equity loan based on a 30-year loan,based on past records. Interest Rate 0.0\% 6.5\% 7.0\% 7.5\% >7.5\% Probability 0.20 0.23 0.25 0.28 .04 -{Equity Loan Rates Narrative} What approach was used in estimating the probabilities for the interest rates?

Cysts After researching cysts of a particular type,a doctor learns that out of 10,000 such cysts examined,1,500 are malignant and 8,500 are benign.A diagnostic test is available which is accurate 80% of the time (whether the cyst is malignant or not).The doctor has discovered the same type of cyst in a patient. -{Cysts Narrative} In the absence of any test,what is the probability that the cyst is benign?

If A and B are mutually exclusive,their joint probability is ____________________.

Messenger Service Three messenger services deliver to a small town in Oregon.Service A has 60% of all the scheduled deliveries,service B has 30%,and service C has the remaining 10%.Their on-time rates are 80%,60%,and 40% respectively.Define event O as a service delivers a package on time. -{Messenger Service Narrative} Calculate P(C and O).

If two events are mutually exclusive,their joint probability is ____________________.

If two events are mutually exclusive,what is the probability that both occur at the same time?

The ____________________ rule is used to calculate the joint probability of two events.

If the outcome of event A is not affected by event B,then events A and B are said to be

Which of the following is an approach to assigning probabilities?

If events A and B have nonzero probabilities,then they can be both independent and mutually exclusive.

____________________ can find the probability that someone with a disease tests positive by using (among other things)the probability that someone who actually has the disease tests positive for it.

There are situations where we witness a particular event and we need to compute the probability of one of its possible causes.____________________ is the technique we use to do this.

Drunk Drivers Six hundred accidents that occurred on a Saturday night were analyzed.Two items noted were the number of vehicles involved and whether alcohol played a role in the accident.The numbers are shown below: Number of Vehieles Involved Did aloholplay a role? 1 2 3 Totals Yes 75 125 50 250 Na 50 225 75 350 Totals 125 350 125 600 -{Drunk Drivers Narrative} If alcohol was not involved,what proportion of the accidents were multiple vehicle?

Condo Sales and Interest Rates The probability that condo sales will increase in the next 6 months is estimated to be 0.30.The probability that the interest rates on condo loans will go up in the same period is estimated to be 0.75.The probability that condo sales or interest rates will go up during the next 6 months is estimated to be 0.90. -{Condo Sales and Interest Rates Narrative} What is the probability that both condo sales and interest rates will increase during the next six months?

Cars Suppose X = the number of cars owned by a family in the U.S.The probability distribution of X is shown in the table below. X 0 1 2 3 Probability 0.56 0.23 0.12 0.09 -The probability of an intersection of two events is called a(n)____________________ probability.