00:01
So this one is normally distributed with a mean of 4 .1 and a standard deviation of 0 .6.
00:06
The data item, or z is almost, i can't spit it out.
00:11
Z is always the data item minus the mean.
00:15
So in part a, when you want the probability that x is between 3 .7 and 4 .4, that's the probability that z is between negative 0 .6 repeating and 0 .5.
00:37
By my calculator is 0 .439897.
00:47
B, you want x is greater than 0 .5 times the standard deviation, which is the same as x is greater than 0 .3, which is the same as z is greater than 0 .5, which by my calculator is 0 .308 .54.
01:13
C, you want the 80th percent.
01:15
Tile x is less than some value k is 0 .8 z in this case is 0 .84 162 and k is z times the standard deviation plus the mean which is 4 .604972 which means 80 % of cats weigh less than roughly 4 .6 in d, you want the probability that x is greater than 4 .5, which is the probability that z is greater than 0 .6 repeating, which is 0 .74 -7507531.
02:20
Using my calculator...