Answer: D
Step-by-step explanation:
Standard Deviation σ2 =
Σ(xi - μ)2/N
=(1 - 5.3)2 + ... + (9 - 5.3)2/10
=68.1/10
= 6.81
σ = √6.81
= 2.60959767014
B) σ2 =
Σ(xi - μ)2/N
=(3 - 61.7)2 + ... + (99 - 61.7)2/10
=58414.1/10
= 5841.41
σ = √5841.41
= 76.429117488036
C) (1 - 11.4)2 + ... + (1 - 11.4)2/10
=8758.4/10
= 875.84
σ = √875.84
= 29.59459410095
D) (79 - 79)2 + ... + (79 - 79)2/10
=0/10
= 0
σ = √0
= 0
I hope this helps, mark as Brainliest please.
Answer:
x=-8 and y=9
Step-by-step explanation:
rewrite the equations to x+2y=10,3x+4y=12
sub 2y from both sides x+2y-2y=10-2y
substitue x=10-2y in 3x +4y=12
3(-2y+10)+4y=12
distribute
add-30 to both sides
divide both sides by -2
y=9
sustitute 9 for y in -2y+10=x
x=-8
Tangent always meets radius at 90° angle.
Angle ABC = 90° so Pythagoras' theorem applies.
r² + 4² = (r+2)²
r² + 16 = r² + 4r + 4
12 = 4r
r = 3