Answer:
Check the explanation
Step-by-step explanation:
Let X denotes steel ball and Y denotes diamond
 = 1/9( 50+57+......+51+53)
 = 1/9( 50+57+......+51+53)
=530/9
=58.89
 = 1/9( 52+ 56+....+ 51+ 56)
= 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
 =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.
 
        
             
        
        
        
If seth goes every three days and Brian im assuming is the name.Goes every five days then they will both go on day 15
        
                    
             
        
        
        
Answer: B.f(n)9n-12
Step-by-step explanation:
 
        
             
        
        
        
Need more information to answer this!!!!
 
        
             
        
        
        
H=-t^2+95
The y intercept here is 95, and it represented from where the boy threw the ball.
If he threw it from 95 ft above the ground, the best answer for where he is is on a bridge.
His backyard is at 0 ft (sea level). An underground cave is below sea level. A ladder is probably not 95 ft.
Final answer: D