Answer:
The answer is D.
Step-by-step explanation:
When x=0, then y=300, so it has to be more than that.
When x=25, y=300, so it has to be less than that.
Answer:
t=411
Step-by-step explanation:
t+55=466
466-55
Subtract the numbers
t=411
Answer:
4 and 5
Step-by-step explanation:
Make a system of equations:
x+y=9
x-y=-1
x=9-y
9-y-y=-1
9-2y=-1
-2y=-10
y=5
Since y=5, x must be 4 since 4+5=9 and 4-5=-1
Hope this helped!
Answer:
Step-by-step explanation:
Hello!
The objective is to estimate the average time a student studies per week.
A sample of 8 students was taken and the time they spent studying in one week was recorded.
4.4, 5.2, 6.4, 6.8, 7.1, 7.3, 8.3, 8.4
n= 8
X[bar]= ∑X/n= 53.9/8= 6.7375 ≅ 6.74
S²= 1/(n-1)*[∑X²-(∑X)²/n]= 1/7*[376.75-(53.9²)/8]= 1.94
S= 1.39
Assuming that the variable "weekly time a student spends studying" has a normal distribution, since the sample is small, the statistic to use to perform the estimation is the student's t, the formula for the interval is:
X[bar] ±
* (S/√n)

6.74 ± 2.365 * (1.36/√8)
[5.6;7.88]
Using a confidence level of 95% you'd expect that the average time a student spends studying per week is contained by the interval [5.6;7.88]
I hope this helps!