A composite sample is taken over a period of time, while a grab sample is a snap shot of what is in your well at the time you take the sample. Homeowner samples are generally grab samples.
Chat with our AI personalities
dont grab her head unless she's into that
on activity page #2
7/10 X 6/9 = 42/90 it can be reduced to 7/15
Let's consider first one bag: The probability to grab one green marble is Pg=1/5 The probability to grab one red marble is Pr=1-Pg=4/5 For the 4 bags, it's a binomial distribution: probability to get k green out of n bags, P(X=k)=nCk pk (1-p)n-k = nCk Pgk Prn-k Now, the probability to grab at least 2 green marbles from 4 bags is 1 - (Probability to get no green marble from 4 bags) - (Probability to get just one green marble from 4 bags) Probability to get no green marble is = 4C0 (4/5)4 = (4/5)4 (n=4, k=0, no green marble from each bag, 4C0 Pr4) Probability to get just one green marble is = 4C1 (1/5) (4/5)3 (n=4, k=1, one green marble from one bag and red marbles from the other ones, 4C1 Pg Pr3) Probability to grab at least 2 green marbles from 4 bags is 1-(4/5)4-4*(1/5)(4/5)3 = 0.1801
Well, honey, it really depends on the size and weight of the toothpicks. On average, there are about 800 toothpicks in a pound. But hey, don't go counting them one by one, that's a sure way to drive yourself crazy! Just grab a handful and go floss your teeth or something, life's too short to be counting toothpicks.