17. The height of pupils in Luna Elementary School has a mean of 121 cm with standard deviation of 5. If 50 of them are taken as samples, what is the probability that their mean height is less than...

17. The height of pupils in Luna Elementary School has a mean of 121 cm with standard deviation of 5. If 50 of them are taken as samples, what is the probability that their mean height is less than 120 cm? 14.61% 11.53% 8.25% 7.93% 18. It is denoted by σ^2 Mode Variance Mean Standard deviation