Answer:
in which class are
Step-by-step explanation:
tell in in this number 9684574163
Answer:
Check the explanation
Step-by-step explanation:
Let X denotes steel ball and Y denotes diamond
= 1/9( 50+57+......+51+53)
=530/9
=58.89
= 1/9( 52+ 56+....+ 51+ 56)
=543/9
=60.33
difference = d =(60.33- 58.89)
=1.44

s12 = 1/9( 502+572+......+512+532) -9/8 (58.89)2
=31686/8 - 9/8( 3468.03)
=3960.75 - 3901.53
=59.22
s1 = 7.69
s22 = 1/9( 522+ 562+....+ 512+ 562) -9/8 (60.33)2
=33295/8 - 9/8 (3640.11)
=4161.875 - 4095.12
=66.75
s2 =8.17
sample standard deviation for difference is
s=![\sqrt{[(n1-1)s_1^2+ (n2-1)s_2^2]/(n1+n2-2)}](https://tex.z-dn.net/?f=%5Csqrt%7B%5B%28n1-1%29s_1%5E2%2B%20%28n2-1%29s_2%5E2%5D%2F%28n1%2Bn2-2%29%7D)
= ![\sqrt{[(9-1)*59.22+ (9-1)*66.75]/(9+9-2)}](https://tex.z-dn.net/?f=%5Csqrt%7B%5B%289-1%29%2A59.22%2B%20%289-1%29%2A66.75%5D%2F%289%2B9-2%29%7D)
= 
=7.93
sd = 
=
=7.93* 0.47
=3.74
For 95% confidence level
=1.96
confidence interval is

=(1.44 - 1.96* 3.75 , 1.44+1.96* 3.75)
=(1.44 - 7.35 , 1.44 + 7.35)
=(-2.31, 8.79)
There is sufficient evidence to conclude that the two indenters produce different hardness readings.
Answer:
Cos a = 3/8.
Step-by-step explanation:
If you want cos a you use the identity cos a = 1 / sec a,
so cos a = 1 / 8/3
= 3/8.
Answer:
a. The mean of the sample is M=35.
The variance of the sample is s^2=39.125.
The standard deviation of the sample is s=6.255.
b. z=-1.6
c. SEM = 2.212
Step-by-step explanation:
The mean of the sample is M=35.
The variance of the sample is s^2=39.125.
The standard deviation of the sample is s=6.255.
<u>Sample mean</u>
<u />
<u>Sample variance and standard deviation</u>
<u />![s^2=\dfrac{1}{(n-1)}\sum_{i=1}^{8}(x_i-M)^2\\\\\\s^2=\dfrac{1}{7}\cdot [(27-(35))^2+(25-(35))^2+(32-(35))^2+(40-(35))^2+(43-(35))^2+(37-(35))^2+(35-(35))^2+(38-(35))^2]\\\\\\](https://tex.z-dn.net/?f=s%5E2%3D%5Cdfrac%7B1%7D%7B%28n-1%29%7D%5Csum_%7Bi%3D1%7D%5E%7B8%7D%28x_i-M%29%5E2%5C%5C%5C%5C%5C%5Cs%5E2%3D%5Cdfrac%7B1%7D%7B7%7D%5Ccdot%20%5B%2827-%2835%29%29%5E2%2B%2825-%2835%29%29%5E2%2B%2832-%2835%29%29%5E2%2B%2840-%2835%29%29%5E2%2B%2843-%2835%29%29%5E2%2B%2837-%2835%29%29%5E2%2B%2835-%2835%29%29%5E2%2B%2838-%2835%29%29%5E2%5D%5C%5C%5C%5C%5C%5C)
![s^2=\dfrac{1}{7}\cdot [(58.141)+(92.641)+(6.891)+(28.891)+(70.141)+(5.64)+(0.14)+(11.39)]\\\\\ s^2=\dfrac{273.875}{7}=39.125\\\\\\s=\sqrt{39.125}=6.255](https://tex.z-dn.net/?f=s%5E2%3D%5Cdfrac%7B1%7D%7B7%7D%5Ccdot%20%5B%2858.141%29%2B%2892.641%29%2B%286.891%29%2B%2828.891%29%2B%2870.141%29%2B%285.64%29%2B%280.14%29%2B%2811.39%29%5D%5C%5C%5C%5C%5C%09%09%09%09%09%09%09%09%09%09%09%09s%5E2%3D%5Cdfrac%7B273.875%7D%7B7%7D%3D39.125%5C%5C%5C%5C%5C%5Cs%3D%5Csqrt%7B39.125%7D%3D6.255)
b. If the population mean is 45, the z-score for M=35 would be:

c. The standard error of the mean (SEM) of this group is calculated as:

Answer: x = -3
Step-by-step explanation:
3x - 9 = -18
1. Add 9 to each side.
3x-9=-18
+9 +9
3x=-9
2. Divide by 3.
3x/3 = -9/3
You are done.
x = -3