Answer:
-0.8 - 0.5b - 1.4c
Step-by-step explanation:
Take the b and the c away
Then times the 0.2 by all the numbers but don't add them
Once your done you and the b and c back to you equation
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.
Option C
The football team had a overall loss of 2 yards
<em><u>Solution:</u></em>
When the team gains yards we use a positive value, and when the team loses yards we use a negative value.
<em><u>Given that, football team gains 2 yards on the first play</u></em>
First play = +2
<em><u>Given that football team loses 5 yards on the second play</u></em>
Second play = -5
<em><u>Given that football team loses 3 yards on the third play</u></em>
Third play = -3
<em><u>Given that football team gains 4 yards on the fourth play</u></em>
Fourth play = +4
Put the yards from four plays together, we get
⇒ 2 -5 -3 + 4
Let us simplify
⇒ -3 -3 + 4 = -6 + 4 = -2
So, -2 represents loss of two yards (since negative value indicates loss)
We can use elimination for these set of systems.
First, we need to set up our variables.
Belts=b
Hats=h
Now, the situation is 6 belts and 8 hats for $140. The situation after is 9 belts and 6 hats for $132.
Let’s set up our system of equations.
6b+8h=140
9b+6h=132
We need to eliminate a variable. Since b has coefficients of 6 and 9, we can easily eliminate b by multiplying the top equation by 3 and the bottom by -2.
18b+24h=420
-18b-12h=-264
Now let’s add.
12h=156
Let’s divide to get h by itself.
156/12=13=h
So a hat costs $13. We need to put in 13 for one of the equations so we can find the cost of a belt.
9b+6(13)=132
9b+78=132
We need b by itself.
9b=54
54/9=6
Belts are $6
We can also use the first equation to check our answers.
6(6)+8(13)
36+104
140.
So, the price of a belt is $6 while the price of a hat is $13.
1/12 if each Question is A-D
