In: Statistics and Probability
The following are closing prices of Google stock for a sample of trading days. Use the 1-Var Stats command in the TI-84 PLUS calculator to compute the sample standard deviation. 455.21 , 482.37, 483.19, 459.63, 497.99, 475.10, 472.08, 444.95, 489.22 Write only a number as your answer. Round to two decimal places (for example 8.32). Your Answer:
For the given sample data set 455.21 , 482.37, 483.19, 459.63, 497.99,:
475.10, 472.08, 444.95, 489.22 to find the Sample standard deviation we need to find the mean first which is calculated as:
Mean = (455.21 + 482.37 + 483.19 + 459.63 + 497.99 + 475.10 +
472.08 + 444.95 + 489.22)/9
= 4259.74/9
, Mean = 473.3044
and the sample standard deviation is calculated as:
Standard Deviation σ = √(1/9 - 1) x ((455.21 -
473.3044)2 + ( 482.37 - 473.3044)2 + ( 483.19
- 473.3044)2 + ( 459.63 - 473.3044)2 + (
497.99 - 473.3044)2 + ( 475.10 - 473.3044)2 +
( 472.08 - 473.3044)2 + ( 444.95 - 473.3044)2
+ ( 489.22 - 473.3044)2)
= √(1/8) x ((-18.0944)2 + (9.0656)2 +
(9.8856)2 + (-13.6744)2 +
(24.6856)2 + (1.7956)2 +
(-1.2244)2 + (-28.3544)2 +
(15.9156)2)
= √(0.125) x ((327.40731136) + (82.18510336) + (97.72508736) +
(186.98921536) + (609.37884736) + (3.2241793600001) + (1.49915536)
+ (803.97199936) + (253.30632336))
= √(0.125) x (2365.68722224)
= √(295.71090278)
= 17.20