I have this question about an exercise I need to make but I have no clue how i could solve this.
'A number of TV's that a shop sell a day, is Poisson distributed with parameter 1.5. How many TV's should the owner buy on Monday, to ensure for 90% that people who buy a TV from Monday until Saturday can take him home immediately?'
Hint...for the six day period, $\lambda=6\times1.5$
If the shopkeeper buys $n$ TVs on Monday, we require that $$p(X\leq n)\geq0.9$$
So have a look at the Poisson tables.