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