<Tr> <Td> Male </Td> <Td> 2135.6 </Td> <Td> Female </Td> <Td> 1956.1 </Td> </Tr> <Tr> <Td> Male </Td> <Td> 2308.7 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Male </Td> <Td> 2950.0 </Td> <Td> </Td> <Td> </Td> </Tr> <P> The graph shows the metabolic rate for males and females . By visual inspection, it appears that the variability of the metabolic rate is greater for males than for females . </P>

What is the standard deviation of variable z