Quantitative Data refers to data (statistics) that can expressed by a certain quantity, numeral value, amount, or range. It can be measured. An example would be: "A yard is three feet".
In contrast, Qualitative data refers to the quality of something. This data cannot be measured. You gather this data by looking at physical attributes or properties. An example would be: "A ripe banana is yellow".
The two hypotheses with data that can be measured (quantitative data) are:
"People who eat low-protein diets are more likely to have less muscle mass"
- The data you are collecting is the amount of muscle mass people who follow a high-protein diet have, compared to the muscle mass of people who follow a low-protein diet.
and "Eating less salt lowers blood pressure over time".
- The data you are collecting is the effect that eating salt has on a person's blood pressure level/range.