Which of the following arguments are valid? Explain your reasoning. (a) I have a student in my class who is getting anA. Therefore, John, a student in my class, is getting an A.

(b) Every Girl Scout who sells at least 30 boxes of cookies will get a prize. Suzy, a GirlScout, got a prize. Therefore, Suzy sold at least 30 boxes of cookies.

Which of the following is the formula for the sequence graphed below

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Consider a bag that contains 220 coins of which 6 are rare indian pennies. for the given pair of events a and b, complete parts (a) and (b) below. 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. a. determine whether events a and b are independent or dependent. b. find p(a and b), the probability that events a and b both occur.