In mary's first math test she scored 87%. the mean and standard deviation for the class were 71% and 18% respectively. in her second math test, mary scored 66%. the mean and standard deviation for the class were 53% and 14% respectively. in which test did mary do better relative to the rest of the class? explain your reasoning. (hint: find the z-scores corresponding to her two test scores.)

Step-by-step explanation:

Since your population are the students in math class, you can use the z-score formula in order to comparing the two math test scores. Where is the mean for the class, is the standars deviation and x is Mary score.

For the first test , so ,.

For the second test , so ,

Mary do better in the second test, relative to the rest of the class (because  , it means the second score is nearer to the mean score of the class than the first one )  

a. the residual plot for model 1 has a random pattern and is a good fit for the data.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this