Answer:
she purchased 6 first class tickets and 2 normal tickets
Step-by-step explanation:
Answer:
See attached picture to view the graph
Step-by-step explanation:
Start by analyzing how this average idea works:
If only one member goes to the trip, it will cost him/her $1000+$200 = $1200.
If two members go to the trip, then they will share the cost as per the following: ($1000+ $200 + $200 = $1400) which they will be dividing into two people, thus costing each of them $700.
Notice that the general function that represents such average will be given by: 
Plot such function in the two dimensional plane, and you will get the asymptotic behavior shown in the attached image.
Answer:

Step-by-step explanation:
For this case we want to find this probability:

Because they want the area to the left of the value. We need to remember that the normal standard distribution have a mean of 0 and a deviation of 1.
We can use the following excel code: =NORM.DIST(-1.55,0,1,TRUE)
And we got:

The other possibility is use the normal standard table and we got a similar result.
Answer:
B: (2,[infinity]]
Step-by-step explanation:
because you will take all numbers bigger than 2 but 2 is not included
C : B = D : E
6 : 5 = D : 3
D = 3.6