To estimate the mean of a normal population whose standard deviation is 6, with a bound on the error of estimation equal to 1.2 and confidence level 99% requires a sample size of at least:

a.166b
b.167
c.13
d. None of these choices

a) 166

Step-by-step explanation:

Explanation:-

Step 1:-

maximum Error of estimation (E) =1.2

we know that maximum Error of estimation

cross multiplication we get ,

E(√n) =σ (zₐ)

Squaring on both sides, we get

Step 2:-

Population of standard deviation σ = 6

level of significance ∝ = 2.576 at 99% of confidence interval

By using formula

substitute all values in above equation

on simplification , we get n = 165.8 ≅166

Conclusion:-

confidence level 99% requires a sample size of at least (n)=166

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation: