Answer:
b = 4
Step-by-step explanation:
The given expression is
Cos (11b + 2) = Sin (12b - 4)
Since, Sin(θ) = Cos(90 - θ)
Therefore, Cos (11b + 2) = Cos [90 - (12b - 4)]
Where 0 < b ≤ 90°
11b + 2 = 90 - (12b - 4)
11b + 2 = 94 - 12b
11b + 12b + 2 = 94 - 12b + 12b
11b + 12b + 2 - 2 = 94 - 2
23b = 92

b = 4
Therefore, b = 4 will be the answer.
Answer:
a) E(X)=1
b) σ=1
c) P(X>1)=0.368
d) P(2<X<5)=0.128
Step-by-step explanation:
We have X: "the time between two successive arrivals at the drive-up window of a local bank", exponentially distributed with λ = 1.
a) We have to compute the expected time between two successive arrivals.
The expected value for X as it is exponentially distributed is:

b) We have to compute the standard deviation of X.
The standard deviation is calculated as:

c) The probability that X is larger than 1 (P(X>1))
We can express the probability as:

d) The probability that X is between 2 and 5 (P(2<X<5))

11.11111111
you can round your answer
divide 27 by 9 you get 3
divide hundred by 9
you get your answer
1/8 or D, because 1/2 divied by 4 equals 1/8. Hope I helped! I need some help on one question for me.