Answer:
The 95% confidence interval for the proportion of students who get coaching on the SAT is (0.1232, 0.147).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of 
.
427 had paid for coaching courses and the remaining 2733 had not.
This means that 
95% confidence level
So 
, z is the value of Z that has a p-value of 
, so 
.
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval for the proportion of students who get coaching on the SAT is (0.1232, 0.147).
The answer is less than or equal to -4. Because -4+8=4
Step-by-step explanation:
y = ax + b
I see already the result (y = x/10 × 1/6), but let's go in formally.
we have multiple function points to use to officially calculate a and b.
1/6 = a×10 + b
2/3 = a×40 + b
5/6 = a×50 + b
1 2/3 = a×100 + b
let's e.g subtract equation 1 from equation 3.
4/6 = a×40 + 0
a = 4/40 / 6 = 4 / 240 = 1/60
1/6 = 10/60 + b
1/6 = 1/6 + b
b = 0
so, the function is
y = x/60
x = 25
y = 25/60 = 5/12 cups
