Solve the below problems:
Z test
Q1: At a retail store, customer survey is South Dallas the average household income of 75 household showed $90K with standard deviation of $25K. At another store in North Dallas, the household income of 60 households surveyed showed $120K with standard deviation of $30K. At significance level of 0.07, can a research analyst conclude that population means are different?
T test
Q2: A random sample of 20 car loans in Ben's finance shows household income of $95K with standard deviation of $18K. A random sample at Citi-Finance of 15 car loans showed household income of $105K with standard deviation of $16K. At significance level of .10, is there a difference in the population means? What inferences could you draw from this test?