Answer:
P = 95%
Step-by-step explanation:
The average is:

The standard deviation is:
.
We want the probability that the red light lasts between 2.5 minutes and 3.5 minutes
This is:

Now we must transform these values to those of a standard normal distribution to facilitate calculation by using the probability tables.

This is:
---------- (By the symmetry of the standard normal distribution)
When you search for the normal standard table, you get the following value:

Answer:
b
Step-by-step explanation:
Answer:
10^3= 10x10x10
Step-by-step explanation:
1000
A) 2/4
b) i: 2/5*1/4= 2/20=1/10
ii:(3/5*2/4)+(2/5*3/4)=(6/20)+(6/20)=3/10+3/10=6/10
c) It seems like there is a lack of information on the tree diagram so I could not answer this.
Hope this helps :)
We have to see the graph to what the answer is. Sorry I wish I could help!