The Law of Cosines features the 3 side lengths of a triangle, plus the measure of the angle opposite one of those sides.
We want angle x, which is opposite the side of length 39.
Then: a^2 = b^2 - 2ab cos C becomes 39^2 = 36^2 + 59^2 - 2(36)(59)cos x
or 1521 = 3481 + 1296 - 2(36)(59) cos x
Subtract (3481+1296) from both sides: 1521 - 4777 = -4248cos x
-3256 = -4248cos x
-3256
Then: cosx = --------------- = 0.766
-4248
Solving for x: x = arccos -0.766 = 0.698 radian, or 40 degrees (answer)
Answer:
(8,5)
Step-by-step explanation:
5x-2y=30
lets substitute "8" as x and see where that takes us
5(8)-2y=30
40-2y=30
subtract 40 on both sides
-2y=-10
divide by "-2" on both sides
y=5
(8,5) is your answer
Answer:
B = 34.2°
C = 58.2° or 121.8°
c= 10.6
Step-by-step explanation:
Step 1
Finding c
We calculate c using Pythagoras Theorem
c²= a² + b²
c = √a² + b²
a= 8, b = 7
c = √8² + 7²
c = √64 + 49
c = √(113)
c = 10.630145813
Approximately c = 10.6
Step 2
Find B
We solve this using Sine rule
a/sin A = b/sin B
A = 40°
a = 8
b = 7
Hence,
8/sin 40° = 7/sin B
8 × sin B = sin 40° × 7
sin B = sin 40° × 7/8
B = arc sin (sin 40° × 7/8)
B ≈34.22465°
Approximately = 34.2°
Step 3
We find C
Find B
We solve this using Sine rule
b/sin B = c/sin C
B = 34.2°
b = 7
c = 10.6
C = ?
Hence,
7/sin 34.2° = 10.6/sin C
7 × sin C = sin 34.2 × 10.6
sin C = sin 34.2° × 10.6/7
C = arc sin (sin 34.2° × 10.6/7)
C = arcsin(0.85)
C= 58.211669383
Approximately C = 58.2°
Or = 180 - 58.2
C = 121.8°
Answer:
a)
, n = 15 , X=3.4 , S=1.5 , α = .05
Formula : 
p- value = 0.607(using calculator)
α = .05
p- value > α
So, we failed to reject null hypothesis
b)
, n =75 , X=20.12 , S=2.1 , α = .10
Formula :
p- value = 0.000412(using calculator)
α = .1
p- value< α
So, we reject null hypothesis
(c) 
, n = 36, p-value = 0.061.
Assume α = .05
p-value = 0.061.
p- value > α
So, we failed to reject null hypothesis
Answer:
0.525 %
Step-by-step explanation:
there is a total of 80 students and 42 received a A or B so 42/80 = 0.525
Hope this helps!
