For a group experiment, your science class measured the fine-particulate concentration in the air at random places around campus, and estimated a sample average of 32 micrograms per cubic meter, if 225 readings were take, and the standard deviation of the sample measurement was 3 you are 99.7% confidence that actual concentration of fine particulates at the school is?

Step-by-step explanation:

In the group experiment, 225 readings were taken, the estimated sample average or mean was 32 micro grams per cubic meter and the standard deviation of the sample measurement was 3.

So here,

n = sample size = 255,

μ = mean = 32,

σ = standard deviation = 3.

We have to find the confidence interval of 99.7% around the mean. For confidence interval of 99.7% z score is 3.

We know that confidence interval is,

Putting the values,

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3

step-by-step explanation:

mean or average is 40.6