Question

question #3
which of the following situations is more likely to include a confounding variable?
o the hospital notices that families with more children have a higher
outstanding balance than families with fewer children.
o a researcher notices that people that own more than three cars live longer
than people that own fewer than three cars.
o a child notices that as the weather begins to cool off, the colors of the leaves
begin to change.
o a teacher notices that her honors - level students scored higher on a test than
the rest of her students.
question #4
an experiment compares the taste of a new coffee blend with the taste of a
successful coffee blend. each of a number of tasters tastes both coffees (in random
order) and says which is better.
this is called a(n) _
o block design experiment
o matched pairs design experiment
o randomized comparative experiment
o observational study

Explanation:

• Question 3:
• A confounding variable is an extraneous variable that is related to both the independent and dependent variables. In the case of "A researcher notices that people that own more than three cars live longer than people that own fewer than three cars", there could be many confounding variables. For example, wealthier people may be able to afford more cars and also have better access to healthcare (which could contribute to longer life).
• In the hospital example, the number of children could directly relate to medical expenses. In the leaf - color example, temperature is the direct cause. In the teacher example, honors - level students are expected to perform better.
• Question 4:
• A matched pairs design experiment is when each experimental unit (in this case, each taster) receives both treatments (tastes both coffees).
• A block design groups experimental units into blocks. A randomized comparative experiment randomly assigns different treatments to different groups of experimental units. An observational study just observes without imposing treatments.

Answer:

• Question 3: A researcher notices that people that own more than three cars live longer than people that own fewer than three cars.
• Question 4: matched pairs design experiment