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 =

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: