At the beginning of the semester, students were asked whether they felt confident with their abilities to get at least a B in the course. After the midterm exam, the same sample of students were asked they were confident in their abilities to get at least a B in the course. The data are presented in the table below. 7. Did students' perceptions of being able to get at least a B in the course change after taking the midterm? a. State your hypotheses. b. Display an appropriate numerical summary. c. What test is appropriate for testing this hypothesis? d. Assess whether the assumptions of this test are appropriate. e. Run the most appropriate test given the reasonableness of the assumptions. Present the test statistic and p-value. f. Interpret the results in the context of the problem. After Midterm Confident Not Confident Total Start Confident Not Confident 30 12 37 27 15 Total 42 22 64

A marketing firm wishes to test the effectiveness of the audio/visual presentation of certain information as opposed to the purely audio presentation of the information.  To this end 100 volunteers were given a 10 minute presentation in which the information was presented in an audio/visual format.  A second group of 100 volunteers was presented the same information in a purely audio format.  Each person in each of the two groups was asked the same 20 questions related to the information in the presentation.   The audio/visual group had an average of 10.5 correct responses with a sample standard deviation of 4.  The purely audio group had an average of 9.4 correct responses with a standard deviation of 3.  The marketing firm believes this means that the audio/visual format leads to better retention of the information. We test the hypotheses H0:  1 -2=0 versus Ha: 1 -2>0 at a 2% level of significance.   Here  denotes  1 the population average number of correct responses for…

A marketing firm wishes to test the effectiveness of the audio/visual presenation of certain information as opposed to the purely audio presentation of information. To this end250 volunteers were given a 10 minute presentation in which the information was presented in an audio/visual format. A second group of 250 volunteers was presented the same information in a purely audio format. Each person in each of the two  groups was asked the same 20 questions related to the infomrstion in the presentation. The audio/visual grouo had an average of 10.2 correct responses with a sample standard deviation of 4. The purely audio group had an average of 9.4 correct responses with a standard deviation of 3. The marketing firm believes this means that the audio /visual format leads to better retention of the information. We test the hypothesed  H1: µ1 - µ2 = 0 versus Ha: µ1-µ>0 at a 2% level of significance. Here µ1 denotes the population average number of correct responses for individuals…

A producer of educational TV shows for gifted children wants to promote the claim that gifted children's scores on an analytical test increase the more the children watch their shows. In RStudio, run the following code to install and/or library the package "openintro". 1. Install.packages("openintro") # don't do this again if you already did this! 2. library(openintro) 3. gifted Delete the install line of code if you are in an RMD file so that it doesn't install every time you knit. The last line of code will access the dataset of that name. dataset named gifted gives information about test scores of gifted children on a standard analytical The test and the number of hours of educational TV these children watch. use the data set to make a model to predict score on analytical skills test (score") from hours of educational TV watched per week (edutv"). a. Make a scatterplot of "score" (y-axis) vs "edutv" (x-axis). Which plot is the scatterplot? Graph A Graph B Graph C Graph Do ỏ A 1954…

The scores of a test for an engineering class of 30 students are shown here. (Due to the nature of this problem, do not use rounded intermediate values in your calculations-including answers submitted in WebAssign.) Scores: 81, 54, 55, 56, 96, 86, 98, 61, 90, 52, 92, 76, 66, 84, 79, 70, 71, 88, 62, 74, 53, 65, 55, 78, 79, 58, 60, 72, 51,80 (a) Determine the frequency (f), midpoint (x), and xf for each range and fill in the table below. (First, organize the scores into the following ranges: 50-59, 60-69, 70-79, 80-89, and 90-99.) (b) Using the following equation, determine the mean value (x) and fill in the table below. Σ(XA) n X = (c) Calculate (x − x) for each range and fill in the table below. (d) Calculate (x - x)²f for each range and fill in the table below. Range Frequency f Midpoint x 50-59 60-69 70-79 80-89 90-99 S = Enter a number. S = (e) Using the following equation, compute the standard deviation of the class scores. Σ(x-x) ²f n - 1 Σ(x-x) ²4 n - 1 = xf 29 X X - X (x - x)²f

Several years ago, the Arcadia school system was criticized because the average Arcadia High School graduate could read at only the ninth-grade level.  After this report was made, a special reading program was established to upgrade skills.  The AHS principal wants to know if the reading program worked.  If it has, he will request that an accreditation team visit the school.  If the program has not improved the reading level to at least 10.0 (sophomore level), the administrator would like to avoid the embarrassment of a poor review.  To determine the average reading level of the senior class, we select ten seniors at random.  We assume that reading scores are normally distributed.  The reading scores for the ten seniors are shown in Table 1.   Table 1: Reading Scores for Sample High School Seniors Student Reading Score 1 13.4 2 12.1 3 11.4 4 10.6 5 10.3 6 10.2 7 9.8 8 9.7 9 9.4 10 8.6   Calculate the sample mean…

Once a computer worm infects a personal computer via an infected e-mail message, it sends a copy to 25-e-mail addresses it finds in the electronic message mailbox on this personal computer. What is the maximum number of different infected computers in the time it takes for the infected message to be forwarded six times? Note: You should count the total of infected computers including the initial one.

Your company wants to assign identification numbers to each of its employees.  The identification number will contain 5 numbers followed by 3 letters.  If repetition is allowed, how many identification numbers can be generated?  Show your work.

A marketing firm wishes to test the effectiveness of the audio/visual presentation of certain information as opposed to the purely audio presentation of the information.  To this end 100 volunteers were given a 10 minute presentation in which the information was presented in an audio/visual format.  A second group of 100 volunteers was presented the same information in a purely audio format.  Each person in each of the two groups was asked the same 20 questions related to the information in the presentation.   The audio/visual group had an average of 10.5 correct responses with a sample standard deviation of 4.  The purely audio group had an average of 9.4 correct responses with a standard deviation of 3.  The marketing firm believes this means that the audio/visual format leads to better retention of the information. We test the hypotheses H0:  1 -2=0 versus Ha: 1 -2>0 at a 2% level of significance.   Here  denotes  1 the population average number of correct responses for…

Please write out the different types of models for the base ten system