Look at screenshot please help

How do you solving the solution of each system using elimination?

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

Select the correct answer from each drop-down menu. james needs to clock a minimum of 9 hours per day at work. the data set records his daily work hours, which vary between 9 hours and 12 hours, for a certain number of days. {9, 9.5, 10, 10.5, 10.5, 11, 11, 11.5, 11.5, 11.5, 12, 12}. the median number of hours james worked is . the skew of the distribution is