The mean time it takes to walk to the bus stop is 8 minutes (with a standard deviation of 2 minutes) and the mean time it takes for the bus to get to school is 20 minutes (with a standard deviation of 4 minutes). The distributions are normal.
a. How long will it take (in minutes), on average, to get to school?
b. What is the standard deviation of the trip to school?
c. What is the probability that it will take longer than 30 minutes to get to school?
Due to a miscalculation, you realize it actually takes an average of 10 minutes to walk to the bus stop.
d. How long will it take (in minutes), on average, to get to school?
e. What is the standard deviation of the trip to school?
f. What is the probability that it will take longer than 30 minutes to get to school?
The only ones I need help with is C and F. I have the answer for the rest of them. Can someone please help me with parts C and F??
365 times 8 = 2920 hr of sleep in a year
Answer:

Step-by-step explanation:
Given : 
On putting
in place of x , we get 
On simplifying , we get 
On differentiating , we get 
Here ,

Now , we need to express it using summation notation.

Answer:
30 degrees
Step-by-step explanation:
Good luck fam
Answer:Ambitious
Vertex: V=(0,0)=(h,k)→h=0, k=0
Opens downward:
(x-h)^2=4p(y-k)
Width focal: p=-6<0 (donwnward)
Replacing h=0, k=0 and p=-6 in the equation above:
(x-0)^2=4(-6)(y-0)
x^2=-24y
Answer: The equation of the parabola is x^2=-24y