this is statistics course and I need help with answering these questions. I attached formulas in case you can use it as a reference.Thank you
II. Probability PM U B) = PM) + P(B] Pull n B) m = Lag?) Var-(X) = 0% = 2m 11:39-19: If X has a binomial distribution with parameters :1 and p, then: P(X = k) = (:)pt(1_ 13)": \"3:74!\" If E la the mean ofa random sample ofsize n from an innite population with mean p and standard deviation 0', then: T 0' \"i=7: III. Inferential Statistics Standardized test statistic: statistic - parameter standard deviation of statistic Confidence interval: statistic + (critical value) . (standard deviation of statistic) Single-Sample Statistic Standard Deviation of Statistic Sample Mean Sample Proportion p(1 - p) n Two-Sample Statistic Standard Deviation of Statistic Difference of sample means n2 Special case when 0 =02 Difference of P (1 - PI) + P2 (1 - P2) sample proportions n 1 n2 Special case when P = P2\farameter will vary according to the sampling distribution. Question 31 1 pts The director of Student Services at The University of Texas is interested in studying whether or not International students feel welcome and comfortable during their first semester on campus. He obtains a list of email addresses of all first-year International students, and emails those students a short questionnaire to complete at their convenience. Which of the following sources of bias is apparent in this survey, and what is the best way to reduce bias? O Wording effect bias; the students should be given the opportunity to rate their comfort on a scale. O Voluntary response bias; only students who have the time and motivation to complete the survey will do so. Non random sampling; the questionnaires should only be emailed to a random sample of students. O Undercoverage bias; International students without email address will not be included in the survey. O Sampling error; students are likely to have varying opinions, so some bias is normal and expected.D Question 30 1 pts Stacy has a Maine Coon cat, one of the largest breeds of domestic cats. She suspects her cat may be slightly overweight, so she decides to do some research on the average weight of all Maine Coon cats. She finds a database online of over 10,000 feline veterinary records, and decides to take five samples of 30 cats from this database to try to determine the mean weight of the Maine Coon breed. Which of the following is true? The values of the population parameter will vary from sample to sample. The parameter has a sampling distribution with the sample statistic as its mean. The sampling statistic can be estimated from the population parameter. The values of the sampling statistic will vary from sample to sample. O The values of the parameter will vary according to the sampling distribution.D Question 28 1 pts The following table describes responses to two questions: "Do you own or rent your home?" and 'Did you take a vacation this year?": Took a Vacation No Vacation Total Owns Home 97 38 135 Rents Home 14 17 31 Total 111 55 166 A student used the above table to calculate the (rounded) probability 0.7185, however the student cleared their calculator and forgot what probability they calculated. The probability the student calculated is most likely: The probability that a randomly selected individual from the survey took a vacation. The probability that a randomly selected individual from the survey owns their home. The probability that a randomly selected individual from the survey rents their home. The probability that a randomly selected homeowner from the survey took a vacation. The probability that a randomly selected homeowner from the survey did not take a vacation.Question 25 1 pts Researchers want to study the effect of using a whitening tray (a mouthpiece-shaped tray filled with a whitening solution) in conjunction with a whitening toothpaste to improve the whiteness of patients' teeth. Suppose that a group of 50 volunteers are divided into two groups: one that will use a whitening toothpaste, and one that will use a whitening toothpaste in addition to a whitening tray for 15 minutes per day. Which of the following is not a valid method for reducing bias in this experiment: O Single-blinding Double-blinding O Blocking for gender Randomization O Replication
