A. (7/13)·(1/3)=7/39. P=7/39
B. (6/13)·(2/3)=12/39. P=12/39
C. (7/13)·(2/3)=14/39. P=14/39
D. (6/13)·(1/3)=6/39. P=6/39
All the numbers from Bag B were written as thirds cause their probabilities could be simplified to make multiplying easier
6 3/4 hours = (6*60)+45 = 405 minutes
7/5 = 1,4
405 minutes * 1,4 = 567 minutes
= Jack spent 9 3/4 hours
So the question is asking to solve for y
You know RS=7y-4
You know ST=y+5
You know RT=28
RS+ST=RT as shown in the diagram, This means that you can use that equation and replace RS,ST, and RT with what you know they are equal too. So you end up with the equation:
(7y-4)+(y+5)=28, Now you have to solve for y
7y-4+y+5=28
8y+1=28
8y=27
y=3.375
With 10 integers available,

has PMF

We're interested in the statistics of the new random variable

. To do this, we need to know the PMF for

. This isn't too hard to find.

Since the PMF for

gives a value of

whenever

is an integer between 0 and 9, it follows that

must also be an integer for the PMF to give the identical value of

. This means

Now the mean (expectation) is


The variance would be




The standard deviation is the square root of the variance, so you have