Data available regarding how much college students paid for textbooks per year showed an average of of $1,302 per year . A student researcher hypothesizes that in 2021 expenditures have decreased primarily due to the introduction of free online textbooks. To test the hypothesis, a sample of 100 students are selected and their expenditures on textbooks is recorded. It is found that the mean of the sample studied was $1250, with a standard deviation of $280. Use a 5% level of significance. s there statistical evidence of a reduction in expenditures on textbooks in 2021? a) State the appropriate test (Type z or t) [1 mark] b) State the null hypothesis (Which is correct: a) HO: / =1302; b) HO: / > 1302; c) HO: M = 1250; d) / 1302; Ha: /