PharmaMax has developed a new experimental medication that they believe will increase the hemoglobin counts in individuals with low hemoglabin. To test their medicine, the researchers give the new medication to 78 adult subjects with low hemoglobin. Forty-three of these subjects experienced a significant increase in their hemoglobin counts. Which of the following options would be an appropriate way to improve this study?

Include people with low hemoglobin in the study to represent a more diverse population.

Repeat the study using only the subjects who did not experience an increase and give them a higher dosage this time.

Use a control group who receive a placebo.

All of these answers are correct.

A group of pediatricians conducted research on 1,300 high school students. The results showed a strong association between the amount of time spent each day on social media and the emotional well being of the student. Select all of the following that are true:

This study cobld not be used to determine causation between the explanatory and response variables because of potential lurking variables.

This is a randomized experiment.

This study could be used to determine causation between the explanatory and response variables because the number of participants is so large.

This is an observational study.

A restaurant manager plans to conduct a survey on employee's wages. They make sure to contact all the employees of the restaurant and ask them to email back their responses to four short and clear majority responses they receive are from employees who wark the night shift like them, What are the lkely source(s) of bias? Select all that apply

Convenience Sample

Volunteer sample

Non-response

Bad Data Frame