Question

Jackson goes to the gym 0, 2, or 3 days per week, depending on work demands. The expected value of the number of days per week that Jackson goes to the gym is 2.05. The probability that he goes 0 days is 0.1, the probability that he goes 2 days is_____ , and the probability that he goes 3 days is____ .

Answer 1

@iGreen @Blonde_Gangsta

Answer 2

@triciaal

Answer 3

I am not current

7 days in one week
0*0.01 + 2x + 3 y = 2.05
x + y = 7
consider
how many outcome for 2 days out of 7?
how many ways 3 days out of 7

let me try and solicit some help

Answer 4

@Michele_Laino will you please help

Answer 5

ok thanks

Answer 6

I think that the requested probability can be found, solving the subsequent system:
\[\Large \left\{ \begin{gathered}
0 \times 0.1 + x \times 2 + y \times 3 = 2.05 \hfill \\
x + y + 0 = 1 \hfill \\
\end{gathered} \right.\]
where x, and y represent the requested probability.
In particular, the second equation means that the sum of all probabilities, has to be equal to 1
Whereas the first equation, comes from the definition of the mean value

Answer 7

ok...@Michele_Laino

Answer 8

@Michele_Laino

Answer 9

what values for x, and for y, do you get?

Answer 10

@Michele_Laino the \(0\) in the second equation should be \(0.1\).

Answer 11

@SithsAndGiggles can you tell me how to do this?

Answer 12

@MrNood can you tell me how to do it?

Answer 13

@welshfella

Answer 14

@amistre64 @jdoe0001

Answer 15

\[E(X)=\sum x_iP(x_i)\]

Answer 16

\[\sum P(x_i)=1\]

Answer 17

x = 0 2 3
P(x) = 0.1 a b

0(.1) + 2a + 3b = 2.05

0.1 + a + b = 1

Answer 18

how would you do the equation? @amistre64

Answer 19

you have 2 equations in 2 unknowns, a very basic algebra setup. Algebra is usually a class taken before stats.