Answer:
A & D
Step-by-step explanation:
A:

D:

Area of rectangle = 12 x 15
= 180 ft
Area of triangle = 1/2(15)4
= 30 ft
Area of entire composite figure= 180+30
= 210 ft
Answer:
140 mile
Step-by-step explanation:

While x is the speed of the second train.
Answer:
The value of the parameter is λ is 0.03692
Step-by-step explanation:
Consider the provided function.
for −∞ < x < ∞.
It is given that standard deviation is given as 38.3 km.
Now we need to calculate the value of parameter λ.
The general formula for the probability density function of the double exponential distribution is: 
Where μ is the location parameter and β is the scale parameter.
Compare the provided equation with the above formula we get.
and μ = 0.
Standard deviation = √2β

Now substitute the value of β in
.

Hence, the value of the parameter is λ is 0.03692