What is the sample variance?   What is the standard deviation?

Best way to explain the difference between variance and standard deviation?

Calculate the expected value, the variance, and the standard deviation of the given random variable X. (Round all answers to two decimal places.) X is the number of red marbles that Suzan has in her hand after she selects four marbles from a bag containing four red marbles and two green ones. expected value variance standard deviation Need Help? Read It

estion Help In a psychology journal, researchers reported that a chief executive officer's facial structure can be used to predict a firm's financial performance. The study involved measuring the facial width-to-height ratio (WHR) for each in a sample of 51 CEOS at publicly traded Fortune 500 firms. These WHR values (determined by computer analyzing a photo of the CEO's face) had a mean of x = 1.81 and a standard deviation of s = 0.12. Use this information to complete parts a and b below. a. Find and interpret a 90% confidence interval for u, the mean facial WHR for all CEOS at publicly traded Fortune 500 firms. (Round to three decimal places as needed.) O A. The 90% confidence interval for mean facial WHR indicates that the true mean facial WHR for the CEOS in the sample is between and with 90% confidence. O B. The 90% confidence interval for mean facial WHR indicates that 90% of all CEOS at publicly traded Fortune 500 firms have a WHR between and O C. The 90% confidence interval for…

N=80  p=.6   mean? variance? standard deviation?

The coefficient of variation CV describes the standard deviation as a percent of the mean. Because it has no​ units, you can use the coefficient of variation to compare data with different units. Find the coefficient of variation for each sample data set. What can you​ conclude? Heights    Weights77    19379    20569    22379    22077    22572    17965    20173    21071    19670    20475    21379    209   CV heights=     % CV weights =     % what can you conclude?

Prof. Torres took her dog Manzy for a walk for 6 days.  These are the number of minutes of each of the 6 days. (Round to hundredths, if needed).  5, 25, 60, 25, 25, 50   What is the mean? What is the sum of squares? What is the sample variance ? What is the sample standard deviation?

z Scores LeBron James, one of the most successful basketball players of all time, has a height of 6 feet 8 inches, or 203 cm. Based on statistics from Data Set 1 “Body Data” in Appendix B, his height converts to the z score of 4.07. How many standard deviations is his height above the mean?

The sample variances target the value of the population variance. true or false?