Suppose your waiting time for a bus in the morning is uniformly distributed on [0, 8], whereas waiting time in the evening is uniformly distributed on [0, 10] independent of morning waiting time. a. If you take the bus each morning and evening for a week, what is your total expected waiting time? [Hint: Define rvs X1, . . . , X10 and use a rule of expected value.] b. What is the variance of your total waiting time? c. What are the expected value and variance of the difference between morning and evening waiting times on a given day? d. What are the expected value and variance of the difference between total morning waiting time and total evening waiting time for a particular week?

Inference for two independent groups: - This means deciding if there’s a statistically significant relationship between explanatory and response variable - If response variable is quantitative, the question involves means o Ex. How does average childhood weight compare between generations - If the response variable is categorical, the question involves proportions o Ex. Does the smoking rate differ between genders Summary of inference for 2 independent population means: - Hypotheses: H 0μ 1μ =2 H A μ1−μ 2¿0 - Sample Statistic: ´ ´ X 1X 2