A test was given to a group of students. Their grades and reactions are summarized below: A B C Total Grumpy 20 18 9 47 Happy 5 13 10 28 Total 25 31 19 75 If one student is chosen at random, find the probability that the student got a 'A' GIVEN they are happy. 31 O 28 O 75 28 O 75 5 O 28Use the spinner below. 12 11 2 10 9 A 8 5 7 6 P (>4) =This data is from a sample. Calculate the mean, standard deviation, and variance. Suggestion: use technology. Round answers to two decimal places. X 28.7 13 47.8 47.1 43.5 44.5 44.6 Mean = Standard Deviation = Variance = Ooops - now you discover that the data was actually from a population! So now you must give the population standard deviation. Population Standard Deviation =