00:02
Alright, so here the question is that the average age of a bunker hill -ciss student is 26 -year -old with a standard deviation of 4 .66 years, right? now, assuming the ages of vhcc students are normally distributed, what percentage of students are at least 32 years old? so here we have to compute the probability for x is greater than equal to 32.
00:29
So this is equal to probability of x minus mean upon standard deviation greater than equal to 32 minus 26 upon 4 .66.
00:39
So this is probability of z greater than equal to 1 .29 or 1 minus the probability of z less than 1 .29.
00:48
So this is equal to 1 minus 0 .9015, which is equal to 0 .0985, right? so in percentage, this is 9 .85%.
01:03
Moving on to the next part of the question, it says that, how old would a student need to be to qualify as one of the oldest 1 % of students on the campus? now, in this case, the probability of z greater than equal to z is equal to 0 .01.
01:19
Right? so the probability for z less than z will be 1 minus 0 .01, that is 0 .99...