using the data below please answer the questions :

What is the average purity for the batches?

What is the median purity for the batches?

What is the variance of purity for the batches?

yield	purity
72.6	60.4
81.7	61.2
75.1	50.7
83	58.6
69.7	69.5
79.1	54.3
71.4	66.5
74.8	59.8
78.1	56
69	64.4
72.8	60.7
82.9	62.2
71.7	61.3
74.6	77.1
80.8	58.1
79.3	54.7
80.1	61.3
58.4	61.2
60.7	61.5
75.7	53.8
77.2	58.8
66	57.3
67.5	63.1
74.2	60.9
64	56.2
75.3	59.4
77.1	59
86.5	63.1
79.7	56
70.8	59.5
82.9	67.3
67	50.5
63.8	62.3
77.6	61.9
85.7	70.2
73.7	54.7
81.2	55
75.9	65.4
81.9	61.7
72.5	64.7
74.5	62.8
90.3	67.5
75.5	63.7
77.3	54.9
73.6	56.3
73.2	61.7
65.5	74.4
65.4	58.5
79.7	71.5
79.2	58.5
80.5	56.6
76.3	61.2
75.7	58
82.4	56.6
79.9	73.5
81.4	65.2
89.3	61.1
82.1	63
68.9	53.5
82.6	59.7
80.3	55.5
80.5	58.9
71.8	63.8
75.9	64.1
75.8	55.5
85.5	58.4
70.3	57.1
83.8	50.3
83.8	61.5
86.1	62.5
76.2	58.6
64.9	56.4
77.1	61.1
75.5	65.8
77.1	57
69.8	58.1
77.6	60.6
80.7	76.9
69.1	62
73.2	58.4
73.7	62.8
75	64.3
75.1	61.3
69.8	63.1
84.4	60.6
79.8	62.5
78.7	75.1
74.8	56.7
73.7	58.7
79.9	59.4
77.5	81.7
72.8	54.5
72.1	58.9
72.8	63
85.1	68.7
84.1	65.3
77.5	55.4
74.6	60
64.6	56.1
65.1	65
82.5	54.3
75	74.8
76.9	65.4
97.1	71.1
73.5	61.3
71.1	62.8
80.1	55.5
67.7	81.4
72.7	64.6
63.5	71.3
72.5	61.8
77.8	56.1
78.6	61.3
71.6	57.3
73.8	60.4
77.7	60.6
74.6	58.8
59.3	59.5
79.1	66.4
81.5	57.1
73.5	59.8
73.6	57.5
79.4	65.6
66.9	68.5
56.9	60.4
66.2	58.4
74.6	52.3
73.9	59.9
69.1	50.2
71.9	61.5
63.5	64.6
78	57.1
60	61.8
86.8	58.3
76.6	58.8
77.9	56.9
63.2	70.1
72.9	77.6
80.5	50.3
74.9	56.8
69.5	60.8
67.7	68.4
70.8	64.8
72	57.5
69.3	62.3
83.6	64.9
71.4	59.9
70.4	61.2
76.3	60.8
68.5	72
81.1	51
61.2	60.3
82.7	61.3
74.9	57.2
73.7	57.3
81.1	59.4
90.1	81.8
76.6	64.9
82.6	55.1
74.1	60.2
70.8	69.5
68.9	54.6
76.5	73.7
85.3	60.4
71.1	58.8
78.2	61.1
79.3	59.3
84.4	64.3
79.8	65.5
68.5	75.8
76.7	57.3
70.3	65.3
83.7	57.6
87.8	65.6
77	51
70.1	65
69.5	57.8
71.3	57.2
80.3	62.8
76.1	55.2
71.2	65.4
77.2	62.5
79	61.1
79.6	58.7
81.7	58.6
79.6	53
70.1	63.9
71.5	65.7
70.5	56.2
64.1	59.3
69.1	58.2
66.2	61.7
85.3	60.8
70	77.5
77.7	51.6
80.4	61.6
77.8	65
77.1	61.6
67.9	76.2
66.6	72.1
74.4	56.9
61.6	62.2
77.2	77.1
68.2	56.8
75.4	50.1
75.5	56.1
75.4	57.5
68.7	60.8
80.5	59.1
75.3	67.3
73.4	53
82.2	59
80.2	60.4
77.3	63.7
75.9	66.3
71.4	64.7
72	56.2
81.2	64.3
72.2	59.8
76.5	63.7
74.6	57.7
73.5	52.7
89.3	57.6
82.1	63.7
80.7	56.9
81.6	66.5
80.5	51.3
74.7	60
74.5	55.4
74.1	50.7
77.8	60.8
76.7	63
72.4	60.2
69.2	59.3
69.5	66.9
69.5	57.6
71.9	56.7
82.6	56
75.5	56.9
73.7	65
64.8	59.1