Answer:
CI = ( 0,1433 ; 0,4067 )
Step-by-step explanation:
College of Engineering
sample size n₁ = 200
sample proportion ( with laptop ) p₁ = 91/ 200 p₁ = 0,455 q₁ = 1 - p₁
q₁ = 0,545
College of Arts
sample size n₂ = 100
sample proportion ( with laptop ) p₂ = 73/ 100 p₂ = 0,73 q₂ = 1 - p₂
q₂ = 0,27
CI = 98 % significance level α = 2 % α = 0,02 α/2 = 0,01
From z-table we find z(c) for 0,01
z(c) = 2,328
CI = [ ( p₂ - p₁ ) ± z(c) * √ (p₁*q₁)/n₁ + (p₂*q₂)/n₂ ]
CI
[ ( 0,73 - 0,455 ) ± 2,328 * √ (0,455*0,545)/ 200 + ( 0,73*0,27)/100
CI = ( 0,275 ) ± 2,328 *√0,00123 + 0,001971
CI = ( 0,275 ± 2,328* 0,0566)
CI = ( 0,275 - 0,1317 ; 0,275 + 0,1317 )
CI = ( 0,1433 ; 0,4067 )
The values of the CI for the difference are always positive meaning that the proportion of students of Arts is greater than the proportion of students of Engineering
