4 students apply to a PhD program.  The program accepts 70% of all applicants.  Students are accepted and rejected independently of each other.  Let the random variable X represent the number of the 4 students who get accepted into the PhD Program. (Hint: Binomial distribution with n=4, P=70%)   What is the standard deviation of the random variable?  (round your answer to 4 decimal places)

A pediatrician would like to study cholesterol level in children 2 to 6 years of age. He randomly selected 5 patients and found their cholesterol levels to be : 185, 220, 250, 169, 189 The mean cholesterol level of this group of patients is?

(04.02 LC) What is the solution to the following system of equations? x − 3y = 62x + 2y = 4

(03.04 LC) The graph of f(x) = 0.6x is replaced by the graph of g(x) = 0.6x + k. If g(x) is obtained by shifting f(x) up by 6 units, then what is the value of k?

When the sample is selected by using subjects that are most easily contacted, what type of sampling is being done?

A variable measured the acidic/base balance of a liquid on the pH scale.  The pH scale exists on a range from 0 (extremely acidic) to 14 (extremely basic).   This variable type is [Answer1] This variable’s categorization is [Answer2]

A researcher is curious to see if the number of after school programs a high school student participates in will influence their likelihood of going to college.  So they take a sample of freshmen high school students and record how many after school programs they participate in each year and then after they graduate check to see if they attended college.  What type of study design is this?

When the sample is selected by picking people based on their position on a list using a sampling interval, what type of sampling is being done?

A researcher is curious to see if the amount of time spent on social media influences how often friends meet in person to socialize.  After their sample is selected the researcher asks the subjects on average how much time they spend on social media each day and then asks their subjects to keep track of how many times they meet in person with their friends to socialize and report back at the end of the month.  What type of study design is this?

A researcher is curious to see if the amount of time spent on social media influences how often friends meet in person to socialize.  After their sample is selected the researcher tells half the sample to spend at least 4 hours each day on social media and the other half to spend no more than 4 hours on social media each day.  Then to report back at the end of the month how many times they meet in person with their friends to socialize.  What type of study design is this?