Answer: (110.22, 125.78)
Step-by-step explanation:
The confidence interval for the population mean is given by :-
Given : Sample size = 463
Significance level : 
Critical value : 
We assume that the population is normally distributed.
Now, the 90% confidence interval for the population mean will be :-
Hence, 99% confidence interval for the mean study time of all first-year students = (110.22, 125.78)
Answer:
p = ½ (x₁ + x₂)
q = a (x₁x₂ − ¼ (x₁ + x₂)²)
Step-by-step explanation:
y = a (x − x₁) (x − x₂)
Expand:
y = a (x² − x₁x − x₂x + x₁x₂)
y = a (x² − (x₁ + x₂)x + x₁x₂)
Distribute a to the first two terms:
y = a (x² − (x₁ + x₂)x) + ax₁x₂
Complete the square:
y = a (x² − (x₁ + x₂)x + ¼(x₁ + x₂)²) + ax₁x₂ − ¼ a(x₁ + x₂)²
y = a (x − ½ (x₁ + x₂))² + a (x₁x₂ − ¼ (x₁ + x₂)²)
Therefore:
p = ½ (x₁ + x₂)
q = a (x₁x₂ − ¼ (x₁ + x₂)²)
Answer:
for quadratic equation 1
y^2-10y+21=0
Step-by-step explanation:
y^2-7y-3y+21=0
y(y-7)-3(y-7)=0
(y-7)(y-3)=0
y-7=0,y-3=0
y=7,y=3
y=(3,7)
for quadratic equation 2
16p^2-8p+1=0
16p^2-4p-4p+1=0
4p(4p-1)-1(4p-1)=0
(4p-1)twice=0
4p-1=0,4p-1=0
4p=1
p=1/4 twice
for quadratic equation 3
x^2-400=0
x^2=400
x=√400
x=20
for quadratic equation 4
-16m^2-8m-1=0
multiply the equation by -
16m^2+8m+1=0
16m^2+4m+4m+1=0
4m(4m+1)1(4m+1)=0
4m+1=0 twice
m=-1/4 twice
for quadratic equation 5
-3n^2+75=0
divide both side by -3
-3n^2/-3=-75/-3
n^2=25
n=√25
n=5
