1. You want to compare the commute times of students who were born in California against
the commute times of students who were not born in California (v6_borninca). Is there a
significant difference in commute times between the two groups?
a. State the null and alternative hypotheses
b. Find the t-statistics and p-value
c. State the conclusion of the significance test in words.
d. What is the 95% confidence interval for the difference? Please explain how this
relates to your conclusion in part c.
2. The variable v6_borninca indicate whether a student was born in CA or somewhere else.
Use this variable to answer the following questions. We are still assuming that our dataset
is a random sample of students living in LA.
a. What is the sample proportion ( ̂)of students who were born in CA?
b. The statistics in part a can be used to estimate the population parameters. What
are the estimated population proportion and its standard error?
c. What is the 95% confidence interval for the estimated proportion of CA-born
students?
3. Is the proportion foreign born among LA students (using our SOCI113 as a sample)
different from the overall state average of 55%1
?
a. State the null and alternative hypotheses
b. Find the test-statistics (z) and p-value
c. State the conclusion of the significance test in words.