Answer:
a) Mean, E(X) = - 0.5
Variance = = 9.25
b) 
or
⇒ 
⇒ 
Step-by-step explanation:
Given:
moment generating function of X as:
MX(t) = 
a) Now
Mean, E(X) =
Thus,

or

also,
Thus,

or

Therefore,
Mean, E(X) = 
or
Mean, E(X) = - 0.5
and

or
= 9.5
also,
Variance(X) = E(X²) - E(X)²
⇒ 9.5 - (-0.5)²
= 9.25
b) Now,
Let f(x) be the PMF of X
Thus,

or
⇒ 
⇒ 
Therefore,
at x = 0, P(x) =
at x= - 4 ,P(x) = 
at x = 5, P(x) =
Thus,
E(X) =
or
E(X) = - 0.5
also,
= 9.5
Hence,
Var(X) = E(X²) - E(X)²
⇒ 9.5 - (-0.5)²
= 9.25
Complete the square since can't factor
2/2=1
add 1 to both sides
x²+2x+1-6=1
factor perfect square
(x+1)²-6=1
add 6 to both sides
(x+1)²=7
sqrt both sides
x+1=+/-√7
minus 1 both sides
x=-1+/-√7
so x=-1+√7 or x=-1-√7
Answer:
The distance of needle cover as it rotate is 0.700688 cm
Step-by-step explanation:
Given as :
The length of the needle = r = 24 cm
The needle is rotated at angle = Ф = 96°
The distance of needle cover as it rotate = length of arc made = l cm
The radius of arc = length of needle = r cm
<u>Now, According to question</u>
The distance of needle cover as it rotate = 
where , π = 3.14
Or, l = 
Or, I = 
Or, l = 75.36 × 0.533°
∵ 180° = 3.14 radian
So, 0.533° = 0.0092978
So, l = 75.36 × 0.0092978
∴ l = 0.700688 cm
So,The distance of needle cover as it rotate = l = 0.700688 cm
Hence, The distance of needle cover as it rotate is 0.700688 cm Answer
Answer:
The measure of a = b = 116 degrees
Step-by-step explanation:
Here, we have value of angles to calculate.
If a and b are both supplementary to c, what this means is that when we add either a or b to c, we get 180
Hence; Mathematically;
a + c = 180 and b + c = 180
What we have here is that a and b must be equal since they are both supplementary to the same angle value
Now, we are told further in the question that the measure of angle a is 12 less than 2 times the measure of c;
Mathematically, this means that;
a = 2c - 12
So we now want to find the measure of b
Let’s substitute for a
2c -12 + c = 180
3c -12 = 180
3c = 180 + 12
3c =192
c = 192/3
c = 64
Thus; a = 2c - 12 = 2(64) -12 = 128 -12 = 116