Question

question in the reply :)

Answer 1

Continuous uniform distribution?
Many students find that sitting through an entire lecture is difficult to do without falling asleep. Suppose the number of minutes a single, randomly selected student is asleep during a lecture is uniformly distributed between 7 and 14 minutes.
B) Over the course of the semester (say, 50 lectures), what is the probability that a randomly selected student will sleep a total of between 130 and 140 minutes?
Assume that the minutes slept in any lecture is independent of the number of minutes slept in any other lectures.
(C) How many lectures must a student attend to be 95% sure that they will have slept at least 28 minutes in total? Use the quadratic equation to solve for the quadratic in this question.
Hint: replace x with sqrt(n) to solve for n.

Answer 2

need more information. need equation to work with.

Answer 3

im not sure what the equation is, thats the problem

Answer 4

then you can't solve those questions unfortunately

Answer 5

maybe you can lol

Answer 6

ye i tried. not sure how tho.

Answer 7

formula is \[1/(\beta - \alpha)\]

Answer 8

1/(14-7)

Answer 9

r u sure? thats what i used for the first part of this question. this part seems more complicated?

Answer 10

1/7 for 7 < x < 14

Answer 11

1/7x from 7 to 14

Answer 12

if you integrate that formula i gave you then it becomes 1/7 (x)
you follow up to that?

Answer 13

i mean 1/7(x) from 130 to 140 mins

Answer 14

ohkay

Answer 15

so the sample size 50 goes where?

Answer 16

you have the final answer by any chance

Answer 17

lol no i dont

Answer 18

the number of lecture should matter because it's uniform random variable

Answer 19

so answer should be approx. 1.4286

Answer 20

how do u get that?

Answer 21

you integrate 1/7
you get (1/7)x
then you take the limit from 140 to 130

Answer 22

are you sure it's 140 and 130 mins?

Answer 23

yeah it is

Answer 24

hmm maybe you're supposed to divide the minutes by 50 lectures

Answer 25

maybe haha.

Answer 26

i think you're supposed to do that then you get .02857 = 2.857%

Answer 27

ok. wud u be able to tell me how u got the limit form 130 to 140?

Answer 28

you first divide 140/50 and 130/50 to get 2.8 and 2.6

Answer 29

then you (1/7)(2.8) - (1/7)(2/6) = .0287

Answer 30

(1/7)(2.8) - (1/7)(2.6) = .0287

Answer 31

ohh okay.thanks :) do u kno how to do parrt C?

Answer 32

not sure since i didn't learn this using quadratic only hypergeometric :( sorry

Answer 33

and binomial

Answer 34

look at your notes and set it equal to .95

Answer 35

good luck

Answer 36

kays np. thanks for ur help :)

Answer 37

lol theres a medal for u :)