A pharmaceutical company conducted a study to test the effectiveness of its new anti-depression medication. 500 adults suffering from depression were selected at random  and were randomly assigned to either a treatment group or a placebo group.  The experiment was double blind. The results were analyzed by the company. What, if any, problems with this study do you notice?

A scientist is studying the effect of a new type of exercise program on cardiovascular health. The scientist randomly assigns individuals to either the exercise program or a control group. The scientist wants to determine if the exercise program has a statistically significant effect on cardiovascular health. The scientist monitors cardiovascular health by measuring the blood pressure of each individual.

Compare and contrast an observational study and experiment. Define the terms "treatment group" and "placebo group" as part of your answer. Also give an example of each.

Please help. Thank you!

You want to compare males and females in their use of coping strategies when engaged in conflict in relationships. You send surveys to couples obtained from marriage license application at the county clerk's office. You identify several distinct coping strategies on the survey and have the respondents rate their use of each strategy on a 7-point scale. You then compare scores that come from the two members of each relationship. If testing hypotheses about the effects of gender on use of coping strategies, it would be most appropriate to calculate a ... 1) independent-samples t 2) one sample t 3) paired samples t 4) z test

Suppose you work as a manager for a large clothing store. You are considering introducing a loyalty program to encourage customers to spend more at your store. Before rolling out your program to the public, you want to do a small experiment to estimate its effectiveness. You offer the loyalty program to 10 random customers, and also observed the sales of 27 random customers who did not get the program as a control group. The customers that were part of the loyalty program had average monthly sales of $302.57 and a sample standard deviation of $49.73. For the control group, the customers had an average monthly sales of $231.65 and a sample standard deviation of $67.88. * Given a 95% confidence interval critical value of t = 2.04, what is the upper bound (upper end) of a 95% confidence interval for the difference between two averages? Use (μloyalty program no loyalty program) for the order. Note: 1- Only round your final answer. Round your final answer to two decimal places.

The Bureau of Labor Statistics reports that the official unemployment rate for Black people was 10.4% and 4.7% for White people in February 2015. Select all correct answers for this question. O The samples of white and black people are independent. The explanatory variable is the unemployment rate. The response variable is the unemployment rate. The response variable is race.

A researcher gathered a sample of participants who volunteered for a studying of phobias. She measured anxiety level of participants as they viewed photos of spiders and again when they viewed puppies. Which statistical test is appropriate for this study and why?

Researchers investigate how the presence of cell phones influence the quality of human interaction.  Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room.  Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment.  What statistical test is appropriate?

You are a sales manager for a grocery store, and you want to see if the introduction of a new sales promotion will increase the sales in your store. To do so, you decided to create an experiment by giving a small sample of customers the promotion before expanding it to a larger customer base. You gave 18 people the promotion, and also observed the sales of 27 people who did not get the promotion as a control group. You found those who received the promotion to have an average monthly sales of $456.60, with a sample standard deviation of $52.23. You found those who did not receive the promotion had an average monthly sales of $361.46, with a sample standard deviation of $56.11. Suppose you want to use hypothesis testing (two-sample test) to investigate if the promotion has increased the sales of your store. Using the order promotion no promotion in your hypothesis test, what is the value of the test statistic for your analysis? Note: 1- Only round your final answer. Round your final…