HW 4 STATS TEST TODAY
Use the following results from a test for marijuana use, which is provided by a certain drug testing company. Among 149 subjects with positive test results, there are22 false positive results; among 154 negative results, there are 55 false negative results. If one of the test subjects is randomly selected, find the probability of a false positive or false negative. (Hint: Construct a table.) What does the result suggest about the test's accuracy?
Step 1 construct a table step 2 find prob of neg find prob of B find prob of A and B add and subtract A and B SEE PAGE 5
Q2 PART B
Find P(A and B), the probability that events A and B both occur. (1/2) * (1/9) =0.0556
P(A or B) indicates
the probability that in a single trial, event A occurs, event B occurs, or they both occur
P(A) + P hat (A) =1 is one way to express
the rule of COMPLEMENTARY EVENTS
When using the _________ always be careful to avoid double-counting outcomes.
ADDITION RULE
A _______ is any event combining two or more simple events.
COMPOUND EVENT
Events that are ______ cannot occur at the same time.
DISJOINT
Q2:A A: When a baby is born, it is a girl. B: When a 9-sided die is rolled, the outcome is 9.
The two events are independent because the occurrence of one does not affect the probability of the occurrence of the other.
MARBLE PROB QUESTION A marble is randomly selected from a bag containing 11 marbles consisting of 1 red, 4 blue, and 6 green marbles. The selected marble is one of the green marbles. B: A second marble is selected and it is the 1 red marble in the bag.
The two events are dependent because the occurrence of one affects the probability of the occurrence of the other and the 5% guideline cannot be applied in this case.
INFO to QUESTION A: When a page is randomly selected and ripped from a 15-page document and destroyed, it is page 13. B: When a different page is randomly selected and ripped from the document, it is page 12. QUESTION PART A a. Determine whether events A and B are independent or dependent. (If two events are technically dependent but can be treated as if they are independent according to the 5% guideline, consider them to be independent.)
The two events are dependent because the occurrence of one affects the probability of the occurrence of the other.
A: When one of the 220 coins is randomly selected, it is one of the 6 Indian pennies. B: When another one of the 220 coins is randomly selected (with replacement), it is also one of the 6 Indian pennies.
The two events are independent because the occurrence of one does not affect the probability of the occurrence of the other.
. Among 146 subjects with positive test results, there are 28 false positive results; among 151 negative results, there are 33 false negative results. If one of the test subjects is randomly selected, find the probability that the subject tested negative or did not use marijuana. (Hint: Construct a table.)
figure number of no's and subtract it by the total of negatives to fill in the table
