Exam 2: Describing Data

Use the following Identify which graphical display might be appropriate in each case. The graphs you may choose from are: -Compare the percentage of people in favor of Barack Obama and Mitt Romney in the 2012 Presidential election for the different regions in the U.S. (Northeast, Southeast, Midwest, West).

Use the following Identify which graphical display might be appropriate in each case. The graphs you may choose from are: -Investigate the relationship between the number of hours of exercise per week and athlete or not for a sample of students at a small university.

Use the following The side-by-side boxplots compare the top 100 men's and women's finishing times in the 2011 New York Marathon. -Does there appear to be an association between gender and race time? Explain.

Use the following Students in an introductory statistics course were asked to count the number of scars on their dominant hand (the one they write with the most). The results are displayed in the provided boxplot. -The distribution of the number of scars would be classified as

Use the following A student working an independent research project wants to investigate if there is an association between the amount of sleep someone gets and their body mass index (BMI) - an indicator of body fatness. For a sample of 45 students, she records their BMI and the average amount of sleep they get on weeknights over a two-week period. -What would it mean for average amount of sleep and BMI to be positively correlated?

Use the following A Fun-Size bag of M&M's contains 5 green, 3 red, 3 yellow, 4 orange, 4 blue, and 2 brown candies. -What proportion of the candies are yellow or orange? Use four decimal places in your answer.

Use the following A student working an independent research project wants to investigate if there is an association between the amount of sleep someone gets and their body mass index (BMI) - an indicator of body fatness. For a sample of 45 students, she records their BMI and the average amount of sleep they get on weeknights over a two-week period. -What would it mean for average amount of sleep to be negatively correlated with BMI?

Use the following Trying to determine the number of students to accept is a tricky task for universities. The Admissions staff at a small private college wants to use data from the past few years to predict the number of students enrolling in the university from those who are accepted by the university. The data are provided in the following table. -Find the correlation between the number of students accepted and enrolled. Use two decimal places in your answer.

Use the following Scores on an exam (out of 100 points) given in a large introductory statistics course are displayed in the provided histogram. -Based on the histogram, which value is likely the mean exam score?

Use the following A student working an independent research project wants to investigate if there is an association between the amount of sleep someone gets and their body mass index (BMI) - an indicator of body fatness. For a sample of 45 students, she records their BMI and the average amount of sleep they get on weeknights over a two-week period. -Suppose the student found a correlation of -0.413 between amount of sleep and BMI. Would it be appropriate for her to conclude that getting more sleep causes individuals to have a lower BMI? Briefly justify your answer.

Use the following Scores on an exam (out of 100 points) given in a large introductory statistics course are displayed in the provided histogram. -Based on the histogram, the standard deviation of the exam scores is likely closest to which of these values?

Use the following The provided Minitab output displays descriptive statistics for the amount of financial aid, in thousands of dollars, awarded to a sample of students at a large university. ‪ -How many students are included in the sample?

Use the following Students in a small statistics course collected data to determine if the length of the forearm could be used to predict the length of the foot (both measured in centimeters). Their data are displayed in the provided table. ‪ -Find the correlation between forearm and foot length. Use three decimal places in your answer.

Use the following Identify which graphical display might be appropriate in each case. The graphs you may choose from are: -Investigate the number of Facebook friends students in your class have.

Which statistic is more resistant to outliers (or extreme data values)?

Use the following A biologist collected data on a sample of 20 porcupines. She wants to be able to predict the body mass of a porcupine (in grams) based on the length of the porcupine (in cm). Her least squares regression equation is , where M is the mass. -Predict the body mass of a porcupine that is 51 cm long. Report your answer using one decimal place.

Another variable that the biologist recorded was the chest circumference (in cm) of the porcupines. Explain what both a negative and a positive association between body mass and chest circumference would mean. Which is more plausible in this situation?

Use the following The finishing time for the top 100 men in the 2011 New York Marathon are displayed in the provided figure. -The mean time for the top 100 males is closest to which value?

Use the following Trying to determine the number of students to accept is a tricky task for universities. The Admissions staff at a small private college wants to use data from the past few years to predict the number of students enrolling in the university from those who are accepted by the university. The data are provided in the following table. -What is the response (Y) variable?

Use the following Students in an introductory statistics course were asked to count the number of scars on their dominant hand (the one they write with the most). The results are displayed in the provided boxplot. -Use the boxplot to estimate the median number of scars that students in the class have on their dominant hand.