Answer:
Brand 1 Brand 2 Difference
37734 35202 2532
45299 41635 3664
36240 35500 740
32100 31950 150
37210 38015 −805
48360 47800 560
38200 37810 390
33500 33215 285
Sum of difference = 2532+ 3664+740+150 −805+ 560 +390 +285 = 7516
Mean = 
Mean = 
a) d= 939.5


=1441.21
b)SD= 1441.21
c)Calculate a 99% two-sided confidence interval on the difference in mean life.
confidence level =99%
significance level =α= 0.01
Degree of freedom = n-1 = 8-1 =7
So, 
Formula for confidence interval 
Substitute the values
confidence interval 
confidence interval
to 
Confidence interval
to 
Answer:
B.
Step-by-step explanation:
If you simple this expression we can see that 7/35 will simplify to 1/5 first. As for the exponents, you can write them out to make it easier to cancel, shown in the photo.
Answer:
9
Step-by-step explanation:
Equation
Sum = s = 180*(n - 2)
Solution
1260 = 180*(n - 2) Divide by 180
1260 / 180 = 180 * (n -2 ) / 180
7 = n - 2 Add 2 to both sides
9 = n
Answer
The polygon has 9 sides.