Bonjour j'aurai besoin d'un coup de pouce den proba/stat svp Voici l'exo
On considère une variable aléatoire discrète X défine par la loi de probabilité suivante :
xi , P(X=xi)
-5 , 1/4
-4 , a
1 , 1/2
2 , 1/8

1/Calculer a
2/Calculer l'espérance et la variance de X

C'est un QCM choix possible A.8.25 , B. 1/8,C.0, et D.-1

Pour 1/ je pense que la somme des P(X=xi) doit être égale à 1 donc réponse 1/8
Pour 2/ je pense qu'il faut d'abord dire qu'elle suit telle type de loi (normale ?) et après esperance = moyenne/médiane non ?

Merci beaucoup d'avance

b.an increase in a causes b to decrease

x=17

step-by-step explanation:

solve 3x-24=x+10

then that makes it 2x=34 because you subtract an x from both sides to get rid of the one on the right, and then you add 24 to both sides to get rid of the 24 on the left

divide by both sides by 2 to get your answer so that you can get your answer

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.