Answer:
The value of 
Step-by-step explanation:
We have given 
d=1.7
We have to find 
So,
from the formula

When n=14




Using the formula:

When n=26
![s_{26}=\frac{26}{2}[2(-18)+(26-1)(1.7)]](https://tex.z-dn.net/?f=s_%7B26%7D%3D%5Cfrac%7B26%7D%7B2%7D%5B2%28-18%29%2B%2826-1%29%281.7%29%5D)
On simplification we get:

It would be 89.
You can also just look up a list of prime numbers online.
This is how I'd set it up:
405/20 = 243/x
this means the mpg (miles / gallons) for 1 situation is the same as the mpg for the other situation (because the rate is the same)
then just cross multiply and solve:
405x=243*20 or 405x=4860 or x = 12
he would need 12 gallons of gas for 243 miles
Answer:
Probability that a customer pays the bill by mail, given that the customer is female is 0.20.
Step-by-step explanation:
The complete question is:
Online By Mail Total
Male 12 8 20
Female 24 6 30
Total 36 14 50
A utility company asked 50 of its customers whether they pay their bills online or by mail. What is the probability that a customer pays the bill by mail, given that the customer is female.
Probability that a customer pays the bill by mail, given that the customer is female is given by = P(Pays bill by mail / Customer is female)
P(Pays bill by mail/Customer is female) = 
Now, Probability that customer is female = 
Also, Probability that customer pays bill by mail and is female = 
So, Required probability = 
= 
=
= 0.20
Hence, probability that a customer pays the bill by mail, given that the customer is female is 0.20.