guess which type of ttest

Question 1

your company wants to improve sales. Past sales data indicate that the average sale was $100 per transaction. After training your sales force, recent sales data (taken from a sample of 25 salesmen) indicates an average sale of $130, with a standard deviation of $15. Did the training work? Test your hypothesis at a 5% alpha level.

Answer 1

one sample t test

because comparing a sample mean to a population mean

Question 2

if has violated assumption of independence

Answer 2

repeated measures ttest

Question 3

if has violated assumption of homogeneity of variance

Answer 3

2 sample ttest with heterogeneous variance

Question 4

which assumption cannot be violated

Answer 4

assumption of normality