Answer:
B.
Step-by-step explanation:
base on my reselarch.. correctly me if im wrong..
To answer this question, first calculate the z-score:
test score - mean score 65 - 70
z = ----------------------------------- = ------------------- = -5/10 = -0.5
std. dev. 10
We need to determine the area under the normal curve to the left of z = -0.5.
Refer to a table of z-scores, and look for z=-0.5. What area appears in connection with this z-score? It's less than 0.5000.
Using my TI-83 Plus calculator (specifically, its "normalcdf( " function, I found that the area under the std. normal curve to the left of z = -0.5 is 0.309.
Thus, the percentile is 30.9, or roughly 31 (31st percentile).
Roughly 31% of students earned a grade lower than 65, and roughly 69% earned a higher grade.
v is 4 more tha x
v=4+x
sum is no more than 14
v+x≤14
sub 4+x for v
4+x+x≤14
4+2x≤14
minus 4 both sides
2x≤10
divide both sides by 2
x≤5
5+4=9
the neighboor's age is 5 years
and victoria is 9
Answer:
6.6 miles
Step-by-step explanation:
due to the construction with the 3 parallel lines, the two crossing lines create 2 similar triangles (same angles and all side lengths and all other lines are all determined by the same multiplication factor going from one triangle to the other).
so,
LM = KL × f
MP = HK × f
HL = LP × f
KL = LM × f
and so on.
and then, also
JL = LN × f
the other thing we know due to the construction (L will always be connected with the middle of HK and MP) : the triangles are isoceles triangle (2 equal sides). in fact, because HK = HL = 2 miles, and it is an isoceles triangle, we also know that KL = 2 miles too.
so, we have
KL = LM × f
2 = 6 × f
f = 2/6 = 1/3
and therefore
JL = LN × f
2.2 = LN × 1/3
LN = 2.2 / 1/3 = 2.2 × 3/1 = 2.2 × 3 = 6.6
so, LN is 6.6 miles long.
Answer:
Step-by-step explanation:
8b - 7 = 7b - 2
Bringing like terms on one side
8b - 7b = - 2 + 7
B = 5
-12 + 5k = 15 - 4k
Bringing like terms on one side
5k + 4k = 15 + 12
9k = 27
k = 27/9 = 3