Explain why two samples from the same population could differ.  Why do we say that two samples test have a built in point of reference?

You are a medical researcher that wants to determine if your new drug can lower people's blood pressure.  You recruit 60 participants with high blood pressure to be part of your study.  You randomly assign participants to one of three groups to receive either 10 mg of your drug, 5 mg, or 0 mg (given as a placebo control).  After 2 weeks, participants' blood pressure is measured and you compare among the 3 groups. Which statistical test would be best to determine if there is a significant difference in blood pressure among the three groups?

Anterior cruciate ligament (ACL) injuries occur most frequently in planting and cutting sports such as basketball, soccer, and volleyball. National collegiate athletic association injury data show that female athletes injure the ACL more frequently than their male counterparts do. A sports medicine professor wants to test this claim. He surveyed 5 universities that had both men's and woman's basketball, soccer, and volleyball and asked them how many grade 3 ACL tears they had during the past 5 seasons. Using the following results, are women at greater risk than men for ACL injuries? (use a standard deviation of 0.01, one tail test). Women- 4,3, 5, 2,4 Men-  2, 0, 1 ,2, 1   Calcualte the sum of squares of injuries for men.

I need help finding the test statistic, p-value, and whether or not to reject the null hypothesis. Please explain each step as well as you can. Thank you very much!

Describe a study in which you can use both nonparametric and parametric statistics. A researcher has participants expecting to receive either painful or mild electrical shocks during a study wait in a quarter-full waiting room with other participants. He then measures whether they choose to sit next to other participants or if they sit far away on their own. What is the best test to run for this study and why?

What is the difference from a controlled variable and the control in a scientific experiment?

Design your own within-subjects study. Remember to include your hypothesis, independent variable with at least 3 conditions, how long participants would spend in the conditions, and your dependent variable.

An athletic director proudly states that he has used the average GPAs of the university's sports teams and is predicting a high graduation rate for the teams. Why is this method unsafe? Choose the correct answer below. OA. This method is unsafe because the average GPA may differ for each team. Using the average of the average GPA of each team obscures the possibility that certain teams tend to perform less well in classes. B. This method is unsafe because there is more variation in the GPAs of the athletes than the average GPA of the university's sports teams. Strong students may offset weak students in calculating the average GPAS, which makes it appear more likely that most students are doing well. OC. This method is unsafe because it is dangerous to extrapolate into the future. Classes in university tend to become more difficult, which makes it less likely that the average GPA will hold as time goes on. D. This method is unsafe because there is a minimum GPA required to graduate. If…