A 2011 NBC News survey found that 80% of a sample of 4500 American teens said they owned an MP3 player such as an iPod. Assume that the sample was an SRS. Suppose we computed a large sample 80% confidence interval for the proportion of all American teens who own an MP3 player. This 80% confidence interval.a) would have a smaller margin of error than the 90% confidence interval.
b) could have either a smaller or a larger margin of error than the 90% confidence interval. This varies from sample to sample.
c) would have a larger margin of error than the 90% confidence interval.

The system of Linear equation is x + 2y ≤ 4 and 2x - y > 0

Step-by-step explanation:

Given: Point ( 2 , 1 )

To find: System of Linear Inequalities which contain given point in

              its solution set

There are 2 lines passing through point ( 2 , 1 )

So first we find the equation of both lines

Equation of line using Two-Point form is given by,

Equation of line 1 passing through ( 0 , 2 ) & ( 4 , 0 )

....... (1)

Equation line 2 passing through ( 0 , 0 )  & ( 2 , 1 )

....... (2)

Now from given graph is clear line 1 contain the given point and area shaded by it is toward origin then we have less than equal sign,

⇒ x + 2y ≤ 4

Line 2 is dotted line. So, it does not contain the given point and area shaded by it is toward 4th quadrant then we have greater than sign in it.

⇒ 2x - y > 0

Therefore, The system of Linear equation is x + 2y ≤ 4 and 2x - y > 0