Question

(1 point) An environmentalist wishes to survey Canadians to determine what percentage support strict environmental controls on the Oll and Gas Industry. The environmentalist randomly picks n=900 Canadians, and finds that 636 favour strict environmental controls on the Oil and Gas Industry. (a) Find a 99% confidence interval for p. Use at least four decimal points for your lower and upper bounds. Lower Bound= Upper Bound= (b) Interpret the meaning of the interval you found in part (a). The proportion of all Canadians who support strict environmental controls on the Oil and Gas Industry is somewhere between % and %. (Enter your answer to at least two decimals.)

Answer 1

Given,

$P =\frac{636} {900} = 0.70667$

n = 900

We know that,

$C. I. = p\pm z* {\sqrt{\frac {p_{0}(1 - p_{0})} {n}}}$

Where, z for 99% confidence level is 2.58

Therefore,

$C. I. = 0.70667\pm 2.58* {\sqrt{\frac {2.70667(1 - 2.70667)} {900}}}$

Lower bound = 0.6676

Upper bound = 0.7458

(b)

The proportion of all Canadians who support strict environmental controls on oil and gas industry is somewhere between 66.76% and 74.58%.