Question

Use the lab to assess whether the following statements are true or false. Enter T for true and F for false.

1. A risk ratio and an odds ratio are different names for the same concept. [a]

2. When we write our hypothesis test for an odds ratio, a typical alternative hypothesis is that OR = 1. [b]

3. If there is an association between the two variables in our two-way table, the expected values will be similar to the observed values. [c]

4. We can calculate a chi-square if one of our categorical variables has more than two categories. [d]

Answer 1

1. A risk ratio and an odds ratio are different names for the same concept. (False)

The basic difference is that the odds ratio is a ratio of two odds (yep, it's that obvious) whereas the risk ratio is a ratio of two probabilities.

2. When we write our hypothesis test for an odds ratio, a typical alternative hypothesis is that OR = 1. (False)

a typical null hypothesis is that OR = 1

3. If there is an association between the two variables in our two-way table, the expected values will be similar to the observed values. (True)

4. We can calculate a chi-square if one of our categorical variables has more than two categories. (False)

since more than one categories is enough to calculate chi square.