Find the critical value Za/2 corresponding to a 99.5% confidence level. 0.0025
2.575
2.81
1.96

The correct option is;

2.81

Step-by-step explanation:

The critical value , is found from the z score table as follows, where the the confidence level is 99.5

Therefore, we have α = 1 - 99.5/100 = 1 - 0.995 = 0.005

α/2 = 0.0025

The critical value is thus found from the z-score table value of 1 - 0.0025 = 0.9975

From the z-table, we can find the 0.9975 score on the row  with z = 2.8 where 0.9975 can be located under the 0.1 column giving the critical value as 2.81

12cm

the answer is d

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1