Answer:
x=0
Step-by-step explanation:
0-0=0
Using confidence interval concepts, it is found that:
a) The point estimate is the sample mean.
b) The confidence interval is: 
c) If $1411 is between the bounds of the interval yes, otherwise no.
--------------
- At item a, it asks to provide a point estimate for the population mean, which is the sample mean
--------------
Item b:
- In the spreadsheet, it is possible to find the <em>standard deviation for the sample</em>, thus, the t-distribution is used.
- The confidence interval will be given by:
In which:
- is the sample mean.
- T is the critical value, from the t-distribution, with a two-tailed area of
and n-1 degrees of freedom. - s is the standard deviation for the sample.
- n is the sample size.
--------------
Item c:
We have to check if 1411 is between 
and 
.
- If it is, the interval includes the National Average, otherwise, it does not.
A similar problem is given at brainly.com/question/24232455
In linear algebra, the rank of a matrix
A
A is the dimension of the vector space generated (or spanned) by its columns.[1] This corresponds to the maximal number of linearly independent columns of
A
A. This, in turn, is identical to the dimension of the vector space spanned by its rows.[2] Rank is thus a measure of the "nondegenerateness" of the system of linear equations and linear transformation encoded by
A
A. There are multiple equivalent definitions of rank. A matrix's rank is one of its most fundamental characteristics.
The rank is commonly denoted by
rank
(
A
)
{\displaystyle \operatorname {rank} (A)} or
rk
(
A
)
{\displaystyle \operatorname {rk} (A)}; sometimes the parentheses are not written, as in
rank
A
{\displaystyle \operatorname {rank} A}.
What we know is that the sum of a triangle's internal angles are 180º, and a straight angle makes 180º.
first, we have to find the third internal angle(let's call it n) so that we can use it to find the exterior angle.
(3x + 20) + (4x + 5) + n = 180
simplify:
7x + 25 + n = 180
7x + n = 155
n = 155 - 7x
Now we can add it to the external angle to find x.
(155 - 7x) + (8x + 15) = 180
simplify:
170 + 8x - 7x = 180
170 + x = 180
x = 10
Now we can substitute it to the external angle.
8 x 10 + 15 = 95
the exterior angle is 95º.
