Student in two fifth grade classes were given the same english test. one class of 24 studmets had a mean 86, and the second class of 23 students had a mean of 85. what is the mean for the total number of students in both classes to the nearest 0.1

The mean of the total number of students is 85.5

Step-by-step explanation:

REcall that given n data points, the mean is given by

.

Let us number the students of the 24 students' class from 1 to 24 and the let us number the students of the other class from 25 to 47.

The question is to find the following

REcall the following

Then, from this equations we can deduce that

Therefore,

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

i think its a and d

step-by-step explanation: