Answer:
a) So, she can expect a 2.4 calls per hour.
b) So, the standard deviation is 0.8.
Step-by-step explanation:
We know that probability model below describes the number of repair calls that an appliance repair shop may receive during an hour.
Repair Calls 1 2 3 4
Probability 0.1 0.5 0.3 0.1
a) We calculate how many calls should the shop expect per hour.
We get:

So, she can expect a 2.4 calls per hour.
b) We calculate the standard deviation:

So, the standard deviation is 0.8.
Yes triangles always add up to 180
Answer:
It's volume is of 84.78 cubic inches.
Step-by-step explanation:
Volume of a cylinder:
The volume of a cylinder with radius r and height h is given by:

A cylinder has a height of 12 inches and a radius of 1.5 inches.
This means that 
What is its volume?

It's volume is of 84.78 cubic inches.
Answer: -5100
<u>Step-by-step explanation:</u>
![\sum^4_1[100(-4)^{n-1}]\qquad \rightarrow \qquad a_1=100\ \text{and r = -4}\\\\\\S_n=\dfrac{a_1(1-r^n)}{1-r}\\\\\\\\S_4=\dfrac{100(1-(-4)^4)}{1-(-4)}\\\\\\.\quad=\dfrac{100(1-256)}{1+4}\\\\\\.\quad=\dfrac{100(-255)}{5}\\\\.\quad=20(-255)\\\\.\quad=-5100\\](https://tex.z-dn.net/?f=%5Csum%5E4_1%5B100%28-4%29%5E%7Bn-1%7D%5D%5Cqquad%20%5Crightarrow%20%5Cqquad%20a_1%3D100%5C%20%5Ctext%7Band%20r%20%3D%20-4%7D%5C%5C%5C%5C%5C%5CS_n%3D%5Cdfrac%7Ba_1%281-r%5En%29%7D%7B1-r%7D%5C%5C%5C%5C%5C%5C%5C%5CS_4%3D%5Cdfrac%7B100%281-%28-4%29%5E4%29%7D%7B1-%28-4%29%7D%5C%5C%5C%5C%5C%5C.%5Cquad%3D%5Cdfrac%7B100%281-256%29%7D%7B1%2B4%7D%5C%5C%5C%5C%5C%5C.%5Cquad%3D%5Cdfrac%7B100%28-255%29%7D%7B5%7D%5C%5C%5C%5C.%5Cquad%3D20%28-255%29%5C%5C%5C%5C.%5Cquad%3D-5100%5C%5C)
Answer:
2 vertical asymptotes occurring at x = 5 and x = -1
Step-by-step explanation:
given

recall that asymptotic occur at the locations that will make the equation undefined. In this case, the asymptote will occur at x-locations which will cause the denominator to become zero (and hence undefined)
Equating the denominator to zero,
(x-5)(x+1) = 0
(x-5) =0
x = 5 (first asymptote)
or (x+1) = 0
x = -1 (2nd asymptote)