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:

Step-by-step explanation:
GIVEN: Suppose that in a certain county
of voters are registered as Democrats,
as Republicans,
as Green party, and the rest are considered Independents. You conduct a poll by calling registered voters in the county at random.
TO FIND: Probability that the first call will be to either a Democrat or a Republican.
SOLUTION:
Lets total population of county be
.
voters registered as Democrats 
voters registered as Republicans 
voters registered as Green party 

Probability that first call will be to Democrats

Probability that first call will be to Republican

probability that the first call will be to either a Democrat or a Republican



Hence the probability that the first call will be to either a Democrat or a Republican is 
Answer:
6x - 6
Step-by-step explanation:
<em>The only step necessary here is to simplify. We can subtract 18 from 12 since they are like terms. </em>
6x - 6.
<em>That's it! That's your final answer. </em>
The ordered pair (6 , 4) is a solution for y - 4 = 7(x - 6)
Step-by-step explanation:
The point-slope form of a linear equation is:
, where
- m is the slope of the line
is a point on the line
Any point on the line is a solution for the equation of the line
The solution of an equation is the values of x and y which make the left hand side is equal to the right hand side
∵ The equation is y - 4 = 7(x - 6)
- Compare the equation by the point-slope form above
∴ m = 7
∴
= 6 and
= 4
- That means point (6 , 6) lies on the line
∴ Point (6 , 4) is a point on the line which represents the
given equation
∵ Any point on a line is a solution of the equation of that line
∴ (6 , 4) is a solution of the equation
The ordered pair (6 , 4) is a solution for y - 4 = 7(x - 6)
Learn more:
You can learn more about the linear equations in brainly.com/question/1284310
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