Find the standard deviation of the sample data set.

127 135 128 131 133 127 122

a.
4.4

b.
4.0

c.
19.0

d.
2.0

Option A)  4.4 is the correct standard deviation of the the given data set.

Step-by-step explanation:

We are given the following data set:

127, 135, 128, 131, 133, 127, 122

Formula:

where are data points, is the mean and n is the number of observations.

Solving:

Sum of squares of differences = 4 + 36 + 1 + 4 + 16 + 4 + 49 = 114

Option A) is the correct standard deviation of the the given data set.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

24+x=y

step-by-step explanation: