Answer:
Step-by-step explanation:
Given that that (X) the amount of time lapsed between consecutive trades on the New York Stock Exchange followed a normal distribution with a mean of 15 seconds.
i.e. X is normal with mean = 15 and unknown std deviation 
Given that
i.e. P(
z=-1.475 (from normal table)
Hence 
Using this we find P(X>17) = 
Answer:
Step-by-step explanation:
5x-2y=24
x+2y=12
add the two equations
(5x-2y)+(x+2y)=24+12
6x=36
x=6
Plug in x=6 into any of the two equations
5(6)-2y=24
30-2y=24
-6= -2y
y= 3
x=6
y=3
(6,3)