Answer:
The 95% confidence interval for the true proportion of university students who use laptop in class to take notes is (0.2839, 0.4161).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for population proportion <em>P</em> is:

The information provided is:
<em>x</em> = number of students who responded as"yes" = 70
<em>n</em> = sample size = 200
Confidence level = 95%
The formula to compute the sample proportion is:

The R codes for the construction of the 95% confidence interval is:
> x=70
> n=200
> p=x/n
> p
[1] 0.35
> s=sqrt((p*(1-p))/n)
> s
[1] 0.03372684
> E=qnorm(0.975)*s
> lower=p-E
> upper=p+E
> lower
[1] 0.2838966
> upper
[1] 0.4161034
Thus, the 95% confidence interval for the true proportion of university students who use laptop in class to take notes is (0.2839, 0.4161).
Step-by-step explanation:
let both unknowns be x and y
x = 5y. ......(1)
x + y = 90. ......(2)
sub eqn (1) into eqn (2)
5y + y = 90
6y = 90
y = 90/6
= 15
sub y = 15 to eqn (1)
x = 5y
x = 5 × 15
× = 75
Answer:

Step-by-step explanation:
Using the law if indices
×
= 
Thus to simplify the expression add the 3 exponents
a(b + c) + b(c - a) + c(a - b) ← distribute parenthesis
= ab + ac + bc - ab + ac - bc ← collect like terms
= 2ac
Then the expression simplifies to

Answer: 29 cookies
Step-by-step explanation:
Judging that a "batch" is a dozen which is 12 then...
12 + 12 + 5 = 29
Hope this helps!!! Good luck!!! ;)
Answer:
4.5 tablets.
Step-by-step explanation:
We just divide 9 by 2.