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 = ![d=\frac{7516}{8}](https://tex.z-dn.net/?f=d%3D%5Cfrac%7B7516%7D%7B8%7D)
Mean = ![d=939.5](https://tex.z-dn.net/?f=d%3D939.5)
a) d= 939.5
![\text{Sample Standard deviation, s} = \sqrt{\dfrac{(x-\bar{x})^2}{n-1}}](https://tex.z-dn.net/?f=%5Ctext%7BSample%20Standard%20deviation%2C%20s%7D%20%3D%20%5Csqrt%7B%5Cdfrac%7B%28x-%5Cbar%7Bx%7D%29%5E2%7D%7Bn-1%7D%7D)
![=\sqrt{\dfrac{(2532-939.5)^2+(3664-939.5)^2+(740-939.5)^2 ...+(285-939.5)^2}{8-1}}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B%5Cdfrac%7B%282532-939.5%29%5E2%2B%283664-939.5%29%5E2%2B%28740-939.5%29%5E2%20...%2B%28285-939.5%29%5E2%7D%7B8-1%7D%7D)
=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, ![t_{\frac{\alpha}{2}}=3.499](https://tex.z-dn.net/?f=t_%7B%5Cfrac%7B%5Calpha%7D%7B2%7D%7D%3D3.499)
Formula for confidence interval ![= \left( \bar{X} \pm t_{\frac{\alpha}{2}} \times \frac{s}{\sqrt{n}} \right)](https://tex.z-dn.net/?f=%3D%20%5Cleft%28%20%5Cbar%7BX%7D%20%5Cpm%20t_%7B%5Cfrac%7B%5Calpha%7D%7B2%7D%7D%20%5Ctimes%20%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%20%5Cright%29)
Substitute the values
confidence interval ![= 939.5 \pm 3.499 \times \frac{1441.21}{\sqrt{8}} \right)](https://tex.z-dn.net/?f=%3D%20939.5%20%5Cpm%203.499%20%5Ctimes%20%5Cfrac%7B1441.21%7D%7B%5Csqrt%7B8%7D%7D%20%5Cright%29)
confidence interval
to ![= 939.5 + 3.499 \times \frac{1441.21}{\sqrt{8}} \right)](https://tex.z-dn.net/?f=%3D%20939.5%20%2B%203.499%20%5Ctimes%20%5Cfrac%7B1441.21%7D%7B%5Csqrt%7B8%7D%7D%20%5Cright%29)
Confidence interval
to ![2722.396](https://tex.z-dn.net/?f=2722.396)
Answer:
There are 50 dimes and 110-50 = 60 quarters in the collection.
Step-by-step explanation:
Let D be the number of dimes.
Then the number of quarters is (110-D).
The "value equation" is
10D + 25*(110-D) = 2000.
Simplify and solve for D:
10D + 2750 - 25D = 2000,
-15D = 2000 - 2750,
-15D = -750,
D = %28-750%29%2F%28-15%29 = 50.
Answer:
A.
5
8
−
3
8
=
2
0
B.
5
8
−
3
8
=
2
8
C.
5
8
+
3
8
=
8
8
D.
5
8
+
3
8
=
8
16
Step-by-step explanation:
Answer:
12.4 mg
3117.21 mg
1870.32 mg
Step-by-step explanation:
Answer:
56 ft
Step-by-step explanation:
Perimeter is the distance around the shape
18 x 2 + 10 x 2 =
36 + 20 =
56 ft