Prof Rea’s Exam Q2 A researcher conducted a study to determine if an antidepressant reduces the chance of migraines. He randomly assigned 300 patients to take the antidepressant every day and 300 patients to take a placebo every day. After a certain length of time, he reported the number of migraine days in the patients who took the antidepressant every day and in those who did not take the antidepressant every day. What is the most important reason for the researcher to randomly assign patients to one of the two groups? So that equal amounts of antidepressants and placebo would be used during the experiment. So that the results of the study will generalize. So that the groups are similar, or have no real difference, prior to the treatment. So that there are an equal number of people in both groups.

Prof Rea’s Exam Q11 Given below is a clickable scatterplot that shows the number of non-commercial space launches worldwide and the number of Sociology doctorates awarded in the US.    Sample mean  Sample standard deviation Linear correlation coefficient  Worldwide non-commercial space launches (x) 44.846 5.273 0.789 Sociology doctorates awarded (y) 585.769 32.231   Based on the linear correlation coefficient 0.789, what is the strength and direction of this scatterplot? Explain.  Compute and interpret the slope of the line of best fit in context. Round to two decimal places.  Compute and interpret the y-intercept of the line of best fit in context. Round to two decimal places.  Write the equation of the line of best fit. Use the equation to find the residual for the year 1997 when there were 54 launches and 601 degrees awarded. Based on this scatterplot, do you believe that an increase in worldwide non-commercial space launches will cause the number of sociology doctorates awarded to increase? Explain. 

Exam Question 5 Given below is the sampling distribution of sample proportions from samples of California residents who are equipped with adequate earthquake supplies. What is the value of the population proportion? Explain how you know.  What is the value of the standard error? Explain how you know. How will the standard error change if the sample size is increased? Explain.

Prof Rea’s Exam Q5 The following data represent the amount of time (in minutes) a random sample of ten students enrolled in a college algebra course spent on the homework on “transformation of functions”: [30, 26, 25, 68, 68, 140, 61, 56, 45, 5] Determine the average amount of time a student in the course spent doing the homework. Show the calculation by hand and write the units to earn full credit. Compute the five-number summary for the set of data and draw a box plot. List any outliers. If there are any outliers, indicate them on the graph with an asterisk *. Be sure to label the graph sufficiently. Show all calculations by hand to earn full credit.

Prof Rea’s Exam Q5 Given below is a clickable scatterplot generated from data taken from 11 high school students. What does a point on the scatterplot represent?    

1. This assessment is enabling you to demonstrate your understanding elementary statistics. Use techniques you have learned to solve all problems on the assessment. Points will be earned primarily through the process of solving. Therefore, you will show as much work as possible and will provide justification whenever necessary. Use models, tables, and/or write descriptively when providing explanations. Write your favorite topic from the class in the left-hand bottom corner of the first page. Write something down, even if you don’t know the final answer. The solutions you provide should be of your own original thought. No collaboration/discussion with anyone is permitted or use of any computer system or server, is allowed. Desmos is permitted on this assessment. Please write the desmos function used if you do. If I suspect any part of the work is not your own, you will earn a zero on the assessment and the activity will be reported to the college to be formally processed and permanently recorded. Sign your name on your work and answer template to acknowledge and agree to these terms. 

Prof Rea’s Exam Q8 Given below is a clickable scatterplot generated from data taken from 11 high school students. The LSR line is graphed on the same plane.    Sample mean Sample standard deviation linear correlation coefficient SAT math score (x) 436 160.466 0.976 High school GPA (y) 73.273 14.867 Use the information in the table above to compute the slope and y-intercept of the LSR line. Then write the equation of the LSR line. Round all values to two decimal places. 

Prof Rea’s Exam Q2 A study found that approximately 17.7% of adult American women use antidepressants and approximately 8.4% of adult American men use antidepressants. Suppose we are interested in finding the differences in proportions from independent random samples of adult American women and men who use antidepressants. We randomly survey 279 adult American women and 301 adult American men.  a. Let

Prof Rea’s Exam Question 5. Tara solves the following problem: Suppose the mean wait-time for a telephone reservation agent at a large airline is 43 seconds. A manager with the airline is concerned that business may be lost due to customers having to wait too long for an agent. To address this concern, the manager develops new airline reservation policies that are intended to reduce the amount of time an agent needs to spend with each customer. A random sample of 250 customers results in a sample mean wait time of 42.3 seconds with a standard deviation of 4.2 seconds. Tara’s Solution: Step 1:

Exam Question 2 A local restaurant has studied the behavior of its clients to predict during which time of day they will be the busiest. Given below is a continuous probability distribution that shows the capacity rate for various times of day.   Write a sentence describing the shaded region on the graph in context. Note that you do not need to find the area of the shaded region.   Write the probability notation for the shaded region on the graph above. Shade the region on the graph that corresponds to the capacity rate of the restaurant before 8 am. Find the capacity rate at the restaurant after 8 am using the complement rule. Write probability notation and the calculation in your answer. Around what times of day are the busiest? Explain why you think this.