A Dewar flask is a container designed to prevent heat transfer so that its contents remain hot or cold for a longer period of time. It consists of a double-walled container
in which most of the air has been removed from the space between the walls. Some
household thermoses are Dewar flasks. What heat-transfer processes are prevented
by removing the air between the walls?
a. Conduction and radiation
b. Conduction and convection
C. Convection and radiation
D. Conduction , convection , and radiation

7. see worksheet 1 for values of variables x1, x2 and x3 and answer the following questions: a. for each variable find the mean, median, coefficient of skewness, range and population standard deviation. b. compared to variable x1, how are the mean and median affected by extreme values (outliers) seen in x2 and x3. c. is the median or mean the better measure of location for x2 and x3? explain. d. explain the differences in the magnitudes of the skewness coefficients for the three variables. e. what is the relationship between the range and standard deviation looking across the three variables?