Question

For the following problem, assume normality in the population. The manager of the cosmetics section of a large department store wants to determine whether newspaper advertising really does affect sales. For her experiment, she randomly selects 15 items currently in stock and proceeds to establish a baseline. The 15 items are priced at their usual competitive values, and the quantity of each item sold for a 1-week period is recorded. Then, without changing their price, she places a large ad in the newspaper, advertising the 15 items. Again, she records the quantity sold for a 1-week period. The results follow. No. Sold Before Ad No. Sold After Ad Item (a) Using a = 0.052 tail, what do you conclude? tobt =

*what is the t obt?

* Estimate the size of the real effect.
d̂ =

Answer 1

Solucion Here Ho o t 0 Prem the gwe data nIs, d=-h.6, d= 3.94 4522 Tet itatac t 3.9u/iS d-f IS-1/4 Cutilal Value + 2.1US Herr al t-4522 net un the lumits of t 2us So 9yedt to, the s a evidanca that oe a odvertuwing Sreally does affect sales the nwus papen elfect Si d 1166 3.9u so thare tha effect siae large