00:01
First of all, let's summarize this problem.
00:05
A population of values has a normal distribution with mu equals 121 .3.
00:13
So, mu equals 121 .3.
00:19
And sigma equals 36 .4.
00:28
So you intend to draw a random sample of size n -192.
00:37
Find the probability that a single randomly selected value is less than 1201 .8.
00:48
So n sample size equals 192.
00:55
And the first task is to calculate the probability.
00:59
Probability that some randomly selected value x is less than 121 .8.
01:09
This equals p z less than 121 .8 minus 121 .3 divided by 36 .4.
01:26
After the calculation we can write that p z less than 0 .014.
01:39
And by using that table, using that table, we can find the needed probability 0 .5056...