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:
They are equal
Step-by-step explanation:
320 oz is 20 pounds:))
Answer:
y+20 = 9(x+2)
Step-by-step explanation:
The slope that passes through the points is
m = (y2-y1)/(x2-x1)
= (79- -20)/ (9--2)
= (79+20)/(9+2)
= 99/11
= 9
We can use point slope form to write an equation. It says to use the first point.
y-y1 = m(x-x1)
y--20 = 9(x--2)
y+20 = 9(x+2)
One way to approach this problem is to go ahead and find the actual equation in slope-intercept form.
The slope of the line thru (3,6) and (5,4) is m = (6-4) / (3-5), or -2/2, or -1.
Subbing the known values of m, x and y, we get:
4 = -(5) + b. Then b = 9.
The correct equation (representing the data values in the table) is y = -x + 9.
