Answer: point estimate = 3.88
Margin of error = 0.63
Step-by-step explanation:
Confidence interval is written in the form,
(Point estimate - margin of error, Point estimate + margin of error)
The sample mean, x is the point estimate for the population mean. Let m represent the margin of error. Since the confidence interval is given as (3.25 , 4.51), it means that
x - m = 3.25
x + m = 4.51
Adding both equations, it becomes
2x = 7.76
x = 7.76/2
x = 3.88
Substituting x = 3.88 into x + m = 4.51, it becomes
3.88 + m = 4.51
m = 4.51 - 3.88
m = 0.63
Solution :
Let
be the unit vector in the direction parallel to the plane and let
be the component of F in the direction of
and
be the component normal to
.
Since, 


Therefore, 
From figure,

We know that the direction of
is opposite of the direction of
, so we have



The unit vector in the direction normal to the plane,
has components :


Therefore, 
From figure,

∴ 

Therefore,


Answer:
4z - 15
4(3) - 15
12 - 15
= -3
High school math? really?