 Hello and welcome to the session, the given question says, the mean and standard deviation of marks obtained by 50 students of a class in three subjects, mathematics, physics and chemistry are given below. Subject, a mathematics, physics and chemistry mean is 42, 32 and 40.9 and standard deviation is 12, 15 and 20 respectively. Which of the three subjects shows the highest variability in marks and which shows the lowest? So, let's start with the solution. For determining which subject is more variable, we have to observe from the standard deviation whichever is greater as more variable. So, here the standard deviation of chemistry is highest versus 20. Standard deviation of mathematics is lowest and therefore chemistry shows the highest variability, mathematics shows the lowest variability. And that's our answer is highest variability is of chemistry, lowest is of mathematics. So, this completes the session, hope you have learned it, take care and have a good day.