6.68% of the students scored at least 19 points on this test while the 85 percentile has a test score of 24.08 points
The z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:
P(x > 19) = P(z > 1.5) = 1 - P(z < 1.5) = 1 - 0.9332 = 0.0668
6.68% of the students scored at least 19 points on this test
b) 85 percentile corresponds to a z score of 1.04
The 85 percentile has a test score of 24.08
Find out more at: brainly.com/question/25012216
The answers is 2y+4/9
Hope that helps!! :)
Answer:
(a) 0.20
(b) 31%
(c) 2.52 seconds
Step-by-step explanation:
The random variable <em>Y</em> models the amount of time the subject has to wait for the light to flash.
The density curve represents that of an Uniform distribution with parameters <em>a</em> = 1 and <em>b</em> = 5.
So, 
(a)
The area under the density curve is always 1.
The length is 5 units.
Compute the height as follows:
Thus, the height of the density curve is 0.20.
(b)
Compute the value of P (Y > 3.75) as follows:
![P(Y>3.75)=\int\limits^{5}_{3.75} {\frac{1}{b-a}} \, dy \\\\=\int\limits^{5}_{3.75} {\frac{1}{5-1}} \, dy\\\\=\frac{1}{4}\times [y]^{5}_{3.75}\\\\=\frac{5-3.75}{4}\\\\=0.3125\\\\\approx 0.31](https://tex.z-dn.net/?f=P%28Y%3E3.75%29%3D%5Cint%5Climits%5E%7B5%7D_%7B3.75%7D%20%7B%5Cfrac%7B1%7D%7Bb-a%7D%7D%20%5C%2C%20dy%20%5C%5C%5C%5C%3D%5Cint%5Climits%5E%7B5%7D_%7B3.75%7D%20%7B%5Cfrac%7B1%7D%7B5-1%7D%7D%20%5C%2C%20dy%5C%5C%5C%5C%3D%5Cfrac%7B1%7D%7B4%7D%5Ctimes%20%5By%5D%5E%7B5%7D_%7B3.75%7D%5C%5C%5C%5C%3D%5Cfrac%7B5-3.75%7D%7B4%7D%5C%5C%5C%5C%3D0.3125%5C%5C%5C%5C%5Capprox%200.31)
Thus, the light will flash more than 3.75 seconds after the subject clicks "Start" 31% of the times.
(c)
Compute the 38th percentile as follows:
Thus, the 38th percentile is 2.52 seconds.
Answer:
V≈1282.82
Step-by-step explanation:
V=πr^2h
3=π·72·25
3≈1282.817
