In a study of cell phone use and brain hemispheric dominance, an internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned. construct a 95% confidence interval for the proportion of returned surveys.

find the best point estimate of the population proportion p.

identify the value of the margin of error e.

construct the confidence intreval.

(0.1886,0.5724)

Step-by-step explanation:

Given that in a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned.

Sample proportion of returned surveys =

Sample size n =2457

q =

Std error of proportion =

a)  the best point estimate of the population proportion p.=0.3805

b) Margin of error = 1.96* std error =

c) Confidence interval =

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.