<h2>
Answer with explanation:</h2>
As per given , we have
Sample size : n= 5
Degree pf freedom = : df= 5-1=4


Significance level for 90% confidence = 
Using t-value table , t-critical value for 90% confidence:

Margin of error of
: 
Interpretation : The repair cost will be within $12.39 of the real population mean value
90% of the time.
Answer:
a.b=[-1]
Step-by-step explanation:
This is a dot product of a and b
a.b =[6,-2,3].[2,5, -1] = [12-10-3] =[-1]
Answer:
The system of linear equations are
and 
Step-by-step explanation:
Given : The number of students who chose lunch was 5 more than the number of students who chose breakfast. Let x represent the number of students who chose breakfast and y represent the number of students who chose lunch.
(50 students picked, 25 picked dinner the rest picked lunch and breakfast)
To find : Write a system of linear equations that represents the numbers of students who chose breakfast and lunch ?
Solution :
The number of students who chose breakfast be 'x'
The number of students who chose lunch be 'y'.
The number of students who chose lunch was 5 more than the number of students who chose breakfast.
i.e. 
Now, Total student were 50 and 25 picked dinner the rest picked lunch and breakfast i.e. 25.
So, 
Therefore, the system of linear equations are
and 
So the greatest common factor of 40 and 16 is 8
40/8 : 16/8
5:2
The simplest form of the ratio 40:16 is 5:2
Hope this helps!