The data for this question are found in the sheet 1. These data represent final grades on a Neurobiology exam written on the last day of the final exam period.

1. Calculate the 75% and the 95% confidence intervals around the mean of these grades.

a. 75% CI = [ , ]

b. 95% CI = [ , ]

Data
57	56	94	47	31	52	63	81	57	60
34	35	43	71	67	42	69	19	73	65
61	62	58	92	85	44	63	60	45	45
72		45	65	47	41	71	61	39	52
50		52	28	72	82	37	53	39	55
41		70	84	69	53	38	54	68	60
45	40			63	44	74	44	64	57
57	65			22	76	49	78	62	65
37	34			51	53	70	41	52	42
69	39	70	66			43	73	48	61
35	54	63	59			44	31	44	61
	53	44	71			53	66	65	67
	56	33	34	65	66			53	66
	63	39	68	84	49			54	69
51	61	45	70	65	48			62	42
48	68	81	51	38	8	60	33	79	68
55	49	19	75	53	55	64	83	30	54
71	58	41	57	73	59	54	61	59	65
43	57	73	71	48	42	42			58
58	63	49	59	24	67	32			47
54	52	46	44	46	50	83			64
78	33	27	38	64	32	62	64	77	29
58	42	64	30	55	64	59	65	44	59
41	66	44	38	37	41	60	72	47	30