I think it should be option d
Answer:
a) correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
b) probability for only 2 or less than 2 surgeries in a given day is 0.0536
Step-by-step explanation:
Given data:
mean number is given as 6.2
correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
we know that variance is given as
hence, standard deviation is given as 
thus standard deviation is 2.49
correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
b) probability for only 2 or less than 2 surgeries in a given day is


= 0.002029 + 0.012582+ 0.039006
= 0.053617
= 0.0536
-5.8 - (-8.4)
When we multiply two negatives they become a positive. In this situation, where there is no other number, you can assume there's basically a 1 in that place.
-5.8 - 1(-8.4) would be just as correct. (If this helps visually clarify anything.)
So we take that -1 and multiply it by that -8.4. Multiplying 1 against anything leaves it the same, so we just need to change the sign. Two negatives make a positive.
-5.8 + 8.4
Now we add these together.
This gives us our final answer of 2.6