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:
6/5 or 1 1/5
Step-by-step explanation:
2/5 + 2/5 + 2/5 = 6/5 or 1 1/5
This is the same as multiplying 3 x 2/5 = 6/5 or 1 1/5
Answer:
n = -36
Step-by-step explanation:
The answer is -36 because:
1) We first have to subtract -24 and 12 to find n
-24 - 12 = -36
This is because whenever there are two negative signs, multiply it.
Negative x Negative = Positive
We have to do, 24 + 12 which is 36. Finally, we just put the greater number's sign to the answer. 24 is greater than 12, therefore, we put a negative sign before 36.
Hope this helps!
Answer:
$400
Step-by-step explanation:
all you do is add 320+540+230+450+280+580/6 and the asnwe comes out to 400
What do you mean, "solve"?
y = -4(x-2)² + 4
the line is a parabol with a maximum (2;4)
it's roots are -4(x-2)² + 4 = 0 => (x-2)² = 1 => x-2 = 1 => x = 3
=> x-2 = -1 => x = 1
symetrical axe: x = 2
is that all you need?
