In the Parent-Teen cell Phone Survey conducted by Princeton Survey Research Associates International, 800 randomly sampled 16-17-year-olds living in the US were asked whether they have ever used their cell phone to text while driving. Of the 800 teenagers surveyed, 272indicated that they text while driving. Obtain a 95% confidence interval for the proportion of 16-17-year-olds who text while driving.

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0

answer: (c) m∠qpo + (2x + 16)° = 180°

step-by-step explanation:

the opposite angles of a quadrilateral are supplementary.

so, ∠o + ∠q = 180°   and   ∠p + ∠r = 180°

since ∠r = 2x + 16°, we can use substitution as follows:

∠p + ∠r = 180°

∠p + (2x + 16)° = 180°

i'm assuming that it's c.)   volcanoes built the mountains and earthquakes tore them down.