Exam 2: Descriptive Statistics

Consider a sample on the waiting times (in minutes), at the billing counter in a grocery store, to be 15, 24, 18, 15, 21, 20, 15, 22, 19, 16, 15, 22, 20, 15, and 21. Compute the mean, median, and mode.

The data collected from the customers in restaurants about the quality of food is an example of

If covariance between two variables is near 0, then it implies that

Data collected from several entities over several time periods is

The manager of an automobile showroom studied the time spent by each salesman interacting with the customer in a month apart from the other jobs assigned to them. The data in hours are given below. Using classes 1013, 1417, and so on, show: Using classes 10-13, 14-17, and so on, show: A. The frequency distribution. B.The relative frequency distribution. C. The cumulative frequency distribution. D. The cumulative relative frequency distribution. E.The proportion of salesmen who spend 13 hours of time or less with the customers. F. Prepare a histogram and comment on the shape of the distribution.

The act of collecting data that are representative of the population data is called

Consider the data below. What percentage of students scored grade C?

A survey on the most preferred newspaper in USA listed The New York Times(TNYT), Washington Post(WP), Daily News(DN), New York Post(NYP), and Los Angeles Times (LAT) as the top five most preferred newspapers. The table below shows the preferences of 50 citizens. a. Are these data categorical or quantitative? b. Provide frequency and percent frequency distributions. c. On the basis of the sample, which newspaper is preferred the most?

Suppose that the average time an employee takes to reach the office is 35 minutes. To address the issue of late comers, the mode of transport chosen by the employee is tracked: private transport (two-wheelers and four-wheelers) and public transport. The data on the average time (in minutes) taken using both a private transportation system and a public transportation system for a sample of employees are given below: a. Considering the travel times (in minutes) of employees using private transport. Compute the z-score for the tenth employee with travel time of 29 minutes. b. Considering the travel times (in minutes) of employees using public transport. Compute the z-score for the second employee with travel time of 29 minutes. How does this z-score compare with the z-score you calculated for part a? c. Based on z-scores, do the data for employees using private transport and public transport contain any outliers?

The data on grades (A, B, C, and D) scored by all students in a test is an example of

The average time a customer service executive takes to resolve an issue on a mobile handset is 26.4 minutes. The average time taken to resolve the issue by a sample of 15 such executives are shown below: a. What is the mean resolution time? b. What is the median resolution time? c. What is the mode for these 15 executives? d. What is the variance and standard deviation? e. What is the third quartile?

Compute the relative frequencies for the data given in the table below:

Suppose that you make a fixed deposit of $1,000 in Bank X, and $500 in Bank Y. The value of each investment at the end of each subsequent year is provided in the table: Which of the two banks provide a better return over this time period?

_____ act(s) as a representative of the population.

Compute the standard deviation for the following sample data. 32 41 36 24 29 30 40 22 25 37

For data having a bell-shaped distribution, approximately _____ percent of the data values will be within one standard deviation of the mean.

Compute the geometric mean for the following data on growth factors of an investment for 10 years: 1.10 0.50 0.70 1.21 1.25 1.12 1.16 1.11 1.13 1.22

Eight observations taken for two variables are as follows: a. Develop a scatter diagram with x on the horizontal axis. b. What does the scatter diagram developed in part a indicate about the relationship between the two variables? c. Compute and interpret the sample covariance. d. Compute and interpret the sample correlation coefficient.

Suppose that the average time an employee takes to reach the office is 35 minutes. To address the issue of late comers, the mode of transport chosen by the employee is tracked: private transport (two-wheelers and four-wheelers) and public transport. The data on the average time (in minutes) taken using both a private transportation system and a public transportation system for a sample of employees are given below: a. What are the mean and median travel times for employees using a private transport? What are the mean and median travel times for employees using a public transport? b. What are the variance and standard deviation of travel times for employees using a private transport? What are the variance and standard deviation of travel times for employees using a public transport? c. Comment.

A variable is defined as a