Rylee took five test in science.

each test had a different score.

the mean score of the test was 90%.

the median score of the test was 85%.

based on the information select the two statements it must be true.

- More than half the scores were 85% or greater.

- At least one score was exactly 85%

Step-by-step explanation:

These two answers come from the fact we have a median calculated.

The median of a sample of an odd number of values (like 5 in this case) is one of the values.  So, 85% is a result of one of the tests Rylee took.

Since 85% is the median, it means it has 2 values above and 2 value below... counting the 85% itself, that makes 3 results with 85% or greater.  Since there is only 5 test results in the sample, 3/5 are 85% or greater... so more than half.

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12