Answer:
a)

b) 
Step-by-step explanation:
Part a
Let A the random variable that represent "The arrival time (minutes) for a daily flight from Boston to New York ". And we know that the distribution of A is given by:

We select our starting point a=0 representing 9:05 AM and the amount of minutes between 9:05 am to 9:55 am are 50 ans for this reason b =50
For ths uniform distribution the expected value is given by
where X is the random variable, and a,b represent the limits for the distribution. If we apply this for our case we got:

And the variance is given by:

And the standard deviation by definition is just the square root of the variance:

Part b
If we convert 9:30 AM to our scale we know that we have 25 minutes between 9:05 AM and 9:30 AM.
For this case we want to find this probability: 
And we can find this probability using the complement rule like this:

And we can use the cumulative distribution function given by:

And we got:

Answer:
6/5
Step-by-step explanation:
9×4=36
6×5=30
36/30÷2
18/15÷3
6/5
Answer:
10
Step-by-step explanation:
Using the distance formula, the distance is ...
d = √((x2 -x1)^2 +(y2 -y1)^2)
d = √((-2-4)^2 +(-4-4)^2) = √((-6)^2 +(-8)^2) = √(36 +64)
d = √100 = 10
The distance between the two points is 10 units.
Answer:
The required location on the gird is shown below.
Step-by-step explanation:
Consider the provided expression.
We need to place the indicated product in the proper location on the grid.
First open the parenthesis as shown:


Now add the like terms as shown:

Hence, the required location on the gird is 
Answer:
180
Step-by-step explanation:
Given the ratio = 7 : 3 : 2 = 7x : 3x : 2x ( x is a multiplier ), then
7x = 2x + 75 ( Natasha gets 75 more sweets than Henry )
Subtract 2x from both sides
5x = 75 ( divide both sides by 5 )
x = 15
Thus
total number of sweets = 7x + 3x + 2x = 12x = 12 × 15 = 180