Question 1153148
I am assuming exactly two weeks
This is z between (8500-10000)/2000 and (12000-10000)/2000 or z between -0.75 and +1.

That probability itself is 0.6147
To have 2 weeks would be 4C2*0.6147^2*0.3853^2, which is the binomial for choosing 2 out of 4 weeks with a certain probability for 2.

That is 0.3366