Answer:
The minimum number of cities we need to contact is 96.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence interval 
, we have the following confidence interval of proportions.
In which
Z is the zscore that has a pvalue of 
.
The margin of error is:
95% confidence interval
So 
, z is the value of Z that has a pvalue of 
, so 
.
In this problem, we have that:
The minimum number of cities we need to contact is 96.
You can use elimination to solve systems of equations with 3 equations. I know how to solve systems of equatons with 3 equations, but I use a different process, I don't know how to use the elimination method.
15-6x2=X im not sure if thats right but its what i got
Answer:
There are 10 counters in the bag and you want the 4
As their is only one for the probability is
1/10
There are now 9 counters left in the bag.
You only want the even ones , which are 2 6 8 and 10 ( four has been taken out)
There are only four even counters in the bag of nine counters so the probability is
4/9
As you want both of these to occur, you need to multiply them
1/10 x 4/9 = 49/90
Step-by-step explanation:
