One study, based on responses from 1,017 randomly selected teenagers, concluded that 39% of teenagers cite grades as their greatest source of pressure. use a 0.05 significance level to test the claim that fewer than half of all teenagers in the population feel grades are their greatest source of pressure

The hypothesis formulae will be

H0 : p = 0.5

Ha : p < 0.5

we will reject H0.

Step-by-step explanation:

Number of responses ( n ) = 1017

percentage( p ) = 39% = 0.39

significance level ( ∝ ) = 0.05

P0 = 50% = 0.5

Test the claim that fewer than half of all teenagers feel the pressure

The hypothesis formulae will be

H0 : p = 0.5

Ha : p < 0.5

Perform the test statistic

Test statistic ( Z ) = -6.957

P-value < 0.05   we will reject H0.  

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option