In order to study whether there is a relationship between gender and age at marriage, 50 couples were randomly selected and the age of the bride and groom were recorded.

Which of the following would be a meaningful display of the data from this study?

Side-by-side boxplots

A scatterplot

A histogram

A pie chart

A two-way table

I would also like to confirm my answer:

A study seeks to answer the question, "Does Vitamin C level in the breast milk of new mothers reduce the risk of allergies in their breastfed infants?" The study concluded that high levels of vitamin C (measured in milligrams) were associated with a 30 percent lower risk of allergies in the infants.

In this scenario, "presence of allergies" is what type of variable?

Categorical

Quantitative

For this problem side by side box-plots would be a good choice to show relationship between quantitative variable "age at marriage" and categorical variable "gender".

Advantage of using side by side box-plots is that it shows five point summary of the data which are;

1. minimum value

2. Lower quartile

3. Median value

4. Upper quartile

5. Maximum value

Part 2)

Study: "Does Vitamin C level in the breast milk of new mothers reduce the risk of allergies in their breastfed infants?"

Presence of allergies: Either presence of allergies exists or it doesn't, this is simple yes/no therefore, it is a categorical variable.

Levels of vitamin C: Since levels of vitamin C can be measured (in milligrams) and thus have numerical value therefore, it is a quantitative variable.