In the monthly payment formula r is the percentage rate as a decimal.
To turn a percentage into a decimal, move the decimal point 2 places to the left.
5.7% becomes 0.057
Answer:
a) 
And we can use the probability mass function and we got:
And adding we got:

b)
c) ![P(X>3) = 1-P(X \leq 3) = 1- [P(X=0)+P(X=1)+P(X=2)+P(X=3)]](https://tex.z-dn.net/?f=P%28X%3E3%29%20%3D%201-P%28X%20%5Cleq%203%29%20%3D%201-%20%5BP%28X%3D0%29%2BP%28X%3D1%29%2BP%28X%3D2%29%2BP%28X%3D3%29%5D%20)


And replacing we got:
![P(X>3) = 1-[0.0115+0.0576+0.1369+0.2054]= 1-0.4114= 0.5886](https://tex.z-dn.net/?f=%20P%28X%3E3%29%20%3D%201-%5B0.0115%2B0.0576%2B0.1369%2B0.2054%5D%3D%201-0.4114%3D%200.5886)
d) 
Step-by-step explanation:
Previous concepts
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
Solution to the problem
Let X the random variable of interest, on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
Part a
We want this probability:

And we can use the probability mass function and we got:
And adding we got:

Part b
We want this probability:

And using the probability mass function we got:
Part c
We want this probability:

We can use the complement rule and we got:
![P(X>3) = 1-P(X \leq 3) = 1- [P(X=0)+P(X=1)+P(X=2)+P(X=3)]](https://tex.z-dn.net/?f=P%28X%3E3%29%20%3D%201-P%28X%20%5Cleq%203%29%20%3D%201-%20%5BP%28X%3D0%29%2BP%28X%3D1%29%2BP%28X%3D2%29%2BP%28X%3D3%29%5D%20)


And replacing we got:
![P(X>3) = 1-[0.0115+0.0576+0.1369+0.2054]= 1-0.4114= 0.5886](https://tex.z-dn.net/?f=%20P%28X%3E3%29%20%3D%201-%5B0.0115%2B0.0576%2B0.1369%2B0.2054%5D%3D%201-0.4114%3D%200.5886)
Part d
The expected value is given by:

And replacing we got:

Answer
It takes two steps to solve this problem. Step 1, you must solve the binomial squared. Then combine similar terms.
Answer:
[rad] 2.41
Step-by-step explanation:
Since it gave you the point and the angle to find, you simply just have to solve for the inverse of cot. Remember cot is the opposite of tan, so cot is cos/sin. In that case, we plug into the calc (in radians):
cot^-1(-√5/2)
And we should get 2.41 as our answer!