Consider the below vector x, which you can copy and paste directly into Matlab. The vector contains the final grades for each student in a large linear algebra course. x = [48 80 59 64 75 49 75 48 58 66 75 56 52 83 58 64 64 46 66 61 61 86 61 62 57 60 72 75 67 67 64 80 84 67 59 71 86 80 79 73 68 87 75 55 50 73 81 48 69 60 62 64 53 66 78 68 82 52 81 58 61 71 79 77 64 76 71 68 79 42 63 65 76 77 62 66 53 73 54 65 64 55 61 68 65 49 60 75 60 58 83 62 56 58 55 83 98 48 83 57 49 68 92 39 80 80 64 60 84 66 90 65 58 55 81 72 49 69 61 79 64 51 52 62 80 75 83 57 76 65 51 62 83 60 70 79 49 78 79 77 74 79 77 67 42 71 67 65 96 67 100 60 61 71 66 70 58 69 48 55 66 60 56 50 74 66 40 75 66 81 67 59 65 78 78 67 79 68 87 60 67 77 58 87 57 59 67 58 59 66 75 50 74 66 74 61 69 54 62 64 58 80 75 66 74 73 65 61 66 60 73 84 51 74 63 76 66 76 55 55 81 54 64 99 54 65 68 42 75 95 69 68 85 54 67 56 69 68 68 69 56 60 65 64 68 39 84 67 56 64 78 83 84 81 79 65 65 49 62 72 84 50 77 60 65 71 85 63 73 70 83 68 70 58 65 76 97 63 68 76 69 46 76 77 62 57 55 97 82 86 68 77 69 57 50 74 80 67 62 58 79 51 51 69 78 58 69 61 61 81 54 61 57 100 78 74 78 72 53 61 60 72 36 78 57 71 68 43 70 51 66 88 81 59 77 75 97 41 68 67 63 64 79 57 76 51 64 72 57 79 84 50 72 87 55 72 67 67 78 53 62 55 25 63 51 85 95 83 73 64 68 63 75 92 46 57 67 65 67 65 60 73 62 60 52 84 71 64 61 54 53 73 72 67 79 60 54 85 54 54 52 88 61 64 87 83 74 61 57 63 67 69 48 50 62 65 87 83 59 55 48 53 69 69 87 57 67 71 63 69 71 44 70 58 71 67 75 67 61 77 49 53 81 48 79 66 65 36 84 75 66 64 58 65 53 72 46 62 60 50 77 69 84 56 67 46 75 75 74 55 49 76 63 71 63 79 37 100 67 71 56 74 64 89 68 76 76 56 67 80 63 70 62 56 47 78 53 44 65 74 41 80 58 55 61 51 51 77 88 61 87 56 73 70 38 71 64 40 74 65 69 60 54 76 74 65 67 57 78 88 73 50 89 62 44 85 75 64 63 53 56 47 60 63 52 68 73 49 68 58 61 87 85 74 56 48 74 56 57 61 71 63 77 62 72 61 74 62 68 60 61 75 59 84 62 82 76 82 66 64 61 59 66 55 73 63 65 77 74 60 65 68 50 95 80 55 80 73 60 36 60 68 52 89 46 63 79 50 76 49 75 54 65 85 48 59 80 60 52 62 87 64 83 52 71 63 49 60 31 67 82 41 77 73 62 79 77 64 46 67 82 87 71 68 84 56 70 64 81 76 72 47 68 73 66 51 58 72 56 92 52 65 53 75 64 77 58 74 77 71 68 64 81 74 56 74 67 55 67 55 83 69 58 70 56 70 66 80 56 49 76 76 53 67 83 72 67 73 64 87 40 66 66 62 65 70 73 89 70 66 86 64 61 80 56 65 61 57 67 70 75 65 80 57 65 92 59 76 80 76 65 57 75 66 63 53 55 75 67 45 72 76 62 74 64 69 74 82 87 65 75 76 63 64 65 88 66 76 78 68 63 67 63 74 67 52 60 65 65 77 63 55 50 80 65 80 80 82 67 76 80 53 44 49 71 69 55 70 56 70 62 65 67 80 47 68 64 36 76 47 77 88 58 66 73 85 57 61 81 62 64 65 50 92 73 55 79 51 77 78 51 52 64 84 59 73 66 60 38 64 77 63 70 63 44 64 56 62 65 62 80 78 62 64 60 70 59 56 45 79 70 75 83 48 60 73 65 59 78 53 42 60 72 80 62 61 53 94 48 67 84 57 62 61 81 60 51 66 68 72 59 51 70 68 60 78 74 76 56 45 49 60 66 63 59 44 53 65 91 61 72 57 58 67 94 76 90 76 71 77 70 35 57 52 69 93 64 72 65 77 70 33 69 58 73 49 65 88 84 65 64 62 64 55 44 73 47 88 67 82 82 54 72 45 65 91 71 100 82 40 57 71 86 81 61 71 63 84 62 66 63 68 73 65 80 69 78 92 40 78 87 88]'

(a)	What proportion of students failed the course (i.e., got a mark of less than 50)? (Note that since the answer is a proportion, it must be between 0 and 1.)

(b)	What proportion of students got a B-, B, or B+ (i.e., got a mark between 70 and 79, inclusive)?