Scores on a college entrance examination are normally distributed with a mean of 500 and a standard deviation of 100% of people who write this exam obtain scores between 425 and 575

We have

425 corresponds to a z of

575 corresponds to

So we want the area of the standard Gaussian between -3/4 and 3/4.  

We look up z in the standard normal table, the one that starts with 0 at z=0 and increases.  That's the integral from 0 to z of the standard Gaussian.

For z=0.75 we get p=0.2734. So the probability, which is the integral from -3/4 to 3/4, is double that, 0.5468.

55%

given that triangle abc is transformed two times to get triangle

a"b"c"

first abc is transformed in to a'b'c' as follows:

the coordinates of a are (1,-1) and transformed into a'(-1,1)

similarly b (4,-2) became b'(-4,2) and

c(7,-2) became c'(-7,2)

i.e. (x,y) becomes (-x,-y)

this is nothing but reflection about a point here origin.

thus first transformation is reflection on the origin.

next is exactly shifting 3 units down

source:

step-by-step explanation: