You turn the percentage to a decimal which is 75%=0.75
Total cost = student cost + adult cost
t = 25s + 3(s+3)
t=28s+9
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).
Answer:3.1875
Step-by-step explanation: Simplifying
-3 + 8 + -8(7 + -2a) = 0
-3 + 8 + (7 * -8 + -2a * -8) = 0
-3 + 8 + (-56 + 16a) = 0
Combine like terms: -3 + 8 = 5
5 + -56 + 16a = 0
Combine like terms: 5 + -56 = -51
-51 + 16a = 0
Solving
-51 + 16a = 0
Solving for variable 'a'.
Move all terms containing a to the left, all other terms to the right.
Add '51' to each side of the equation.
-51 + 51 + 16a = 0 + 51
Combine like terms: -51 + 51 = 0
0 + 16a = 0 + 51
16a = 0 + 51
Combine like terms: 0 + 51 = 51
16a = 51
Divide each side by '16'.
a = 3.1875
Simplifying
a = 3.1875
Answer:
(a) 0.2824
(b) 0.0002441
Step-by-step explanation:
Assuming that the population is large enough to behave as a binomial distribution (between whites and non-whites), the probability of 12 out of 12 juros being white is:

Where p(w) is the proportion of the population that is white:
(a) for p = 0.90

The probability is 0.2824.
(b) for p = 0.50

The probability is 0.0002441.