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))

Answer:
Step-by-step explanation:
83/100 is already simplified. You can not make it smaller.
Answer:
the value of the investment after 3 years= £11,904
Step-by-step explanation:
sarah invests £9600 at a simple interest rate of 8% per year
number of years = 3
Formula for simple interest
I = P*n* r
P is the initial amount invested= 9600
r is the rate of interest = 8% = 0.08
n = number of years = 3
Now we find interest using formula
I = 9600 * 0.08 * 3= 2304
Interest amount is 2,304
Now we add the interest with the initial amount to get the value of investment after 3 years
9600 + 2304= 11904
<span>You can check all the rates on the number line by finding the quotient between the top rate and the bottom rate given and make sure that all of your quotients are equal to the given rate. </span>
Answer:
a) 0.82
b) 0.18
Step-by-step explanation:
We are given that
P(F)=0.69
P(R)=0.42
P(F and R)=0.29.
a)
P(course has a final exam or a research paper)=P(F or R)=?
P(F or R)=P(F)+P(R)- P(F and R)
P(F or R)=0.69+0.42-0.29
P(F or R)=1.11-0.29
P(F or R)=0.82.
Thus, the the probability that a course has a final exam or a research paper is 0.82.
b)
P( NEITHER of two requirements)=P(F' and R')=?
According to De Morgan's law
P(A' and B')=[P(A or B)]'
P(A' and B')=1-P(A or B)
P(A' and B')=1-0.82
P(A' and B')=0.18
Thus, the probability that a course has NEITHER of these two requirements is 0.18.