Question

what is the standard deviation for these scores correct to one decimal place

1. The following raw scores were obtained by 30 students on a 100-point test: 40 44 56 94 81 85 76 57 85 45 67 43 60 56 53 85 93 74 72 75 46 96 66 85 92 93 65 85 80 47

Answer 1

sr.no.	x	x-x̅	(x-x̅)2
1	40	-29.8667	892.0178
2	44	-25.8667	669.0844
3	85	15.13333	229.0178
4	43	-26.8667	721.8178
5	53	-16.8667	284.4844
6	74	4.133333	17.08444
7	46	-23.8667	569.6178
8	85	15.13333	229.0178
9	56	-13.8667	192.2844
10	94	24.13333	582.4178
11	81	11.13333	123.9511
12	76	6.133333	37.61778
13	45	-24.8667	618.3511
14	60	-9.86667	97.35111
15	85	15.13333	229.0178
16	72	2.133333	4.551111
17	96	26.13333	682.9511
18	92	22.13333	489.8844
19	65	-4.86667	23.68444
20	80	10.13333	102.6844
21	85	15.13333	229.0178
22	57	-12.8667	165.5511
23	67	-2.86667	8.217778
24	56	-13.8667	192.2844
25	93	23.13333	535.1511
26	75	5.133333	26.35111
27	66	-3.86667	14.95111
28	93	23.13333	535.1511
29	85	15.13333	229.0178
30	47	-22.8667	522.8844
Total	2096		9255.467
mean=x̅	Total/30
x̅	69.86667

X = 69.86667 {(x-x} = 9255.467 standard deviation = {(x-7) 2 - 14255.467 30- g255. 467 29 319 .154 standard deviation = 17.9