Compute the (sample) variance and standard deviation of the data sample. (Round your answers to two decimal places.) −8, 2, 2, 4, 15 variance standard deviation

Respuesta :

Answer:

Variance = 67.00

Standard deviation ≈ 8.19

Step-by-step explanation:

Before we can calculate the standard deviation of the dataset, we need to get the mean value first.

mean = sum of the values/total number given

mean = -8+2+2+4+15/5

mean = 15/5

mean (xbar) = 3

For ungrouped data:

Variance S²=  ∑(xi-xbar)²/N-1

xi are the individual values

xbar is the mean value = 3

N is the total number in the dataset = 5

Variance = (-8-3)²+(2-3)²+(2-3)²+(4-3)²+(15-3)²/5-1

S² = (-11)²+(-1)²+(-1)²+(1)²+(12)²/4

S² = (121+1+1+1+144)/4

S² = 67

Hence the variance of data sample is 67.00

Standard deviation is the square root of the variance.

√S² = Standard deviation

√67 = Standard deviation

Standard deviation = 8.185

Standard deviation ≈ 8.19 (to 2 decimal place)