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
Answer: 
Step-by-step explanation:
88 can be rewritten as 8 x 10 and 8 can be rewritten as 
making a 2 come out of the root.
10 can be rewritten as 2 x 5.
2*2 can also be rewritten as 
making a 2 come out of the root.
We can't keep simplifying the root.
Answer:
B of course you dummy
Step-by-step explanation:
Answer:
1/26
Step-by-step explanation:
There are 4 Jacks in every deck of cards, one for each suit. Therefore your chances of drawing a Jack, or any other card for that matter, are 4 in 52. So, the first probability for cards is 4/52.
Now, for the coin, the probability is 1/2.
So, the probability of getting Jack and hits is 4/52 X 1/2 = 1/26.
X + 2 = 6.2
subtract 2 from both sides
x = 4.2
