D. f(x)= x*-9x^o+2x^2-4x+10
X-y=-1
x+y=5
y=x+1
x+x+1=5
2x+1=5
2x=4
x=2
y=x+1
y=2+1
y=3
Answer: 5.37
Step-by-step explanation:
Let x = ACT scores.
Given: ACT scores have a mean of 20.8 and 9 percent of the scores are above 28. The scores have a distribution that is approximately normal.
i.e. P(X>28)=0.09 (i)
Now,
![P(X>28)=P(\dfrac{X-\mu}{\sigma}>\dfrac{28-20.8}{\sigma})\\\\= P(z>\dfrac{7.2}{\sigma})\ \ \ \ [z=\dfrac{X-\mu}{\sigma}]](https://tex.z-dn.net/?f=P%28X%3E28%29%3DP%28%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%3E%5Cdfrac%7B28-20.8%7D%7B%5Csigma%7D%29%5C%5C%5C%5C%3D%20P%28z%3E%5Cdfrac%7B7.2%7D%7B%5Csigma%7D%29%5C%20%5C%20%5C%20%5C%20%5Bz%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5D)
(ii)
One -tailed z value for p-value of 0.09 =1.3408 [By z-table]
From (i) and (ii)
Hence, the standard deviation = 5.37
3. Yes the cost of each item is proportional because in each pack each t-shirt cost $2.33. You can check that by dividing the amount of money each pack cost by the amount of shirts in each pack. For example the pack of 3 is $7, so 7/3 = $2.33. The pack of 5 cost $11.65, so 11.65/5 = $2.33. And the pack of 7 cost $16.31, so 16.31/7 = $2.33
4) Yes, it is proportional because each x is being squared or multiplied by it’s self.
Answer:
Carly will have to spend $7.25
Step-by-step explanation:
We know that:
1 pound of turkey = $5.80
To find how much 1.25 pounds of turkey will cost, multiply:
5.80 x 1.25 = 7.25
Therefore, 1.25 pounds of turkey will cost $7.25
I really hope this helps!
-SpaceMarsh
