The Vopstra telecommunication companyr has increased its branding of phones in the stores that sell them. To varying degrees, the shelves that contain Vopstra phones now have advertizing in the form of small posters. @Vo PSTRA Different stores contain different amounts of adverzing, and Vopstra would like to know if there is any relationship between amount spent on adverzing (X) and sales of Vopstra phones (Y). A random sample of 50 stores is selected. For each store, the amount in dollars spent on advertizing and the amount in dollars made in sales of Vopstra phones are recorded. The following regression equation is calculated: y: 25.20 + 3.42x Along with this, the following values were calculated: 55x = 180.50 SST = 255.20 se = 29.1? Vopstra plans on conducting a hypothesis test with 90% condence and the following hypotheses: H0: [31 = 0 H1: [3.1 0 You may nd this Student's t distribution table useful. a) Calculate the test statistic (t) for this test. Give your answer to 4 decimal places. t = :l b) The null hypothesis rejected in this test