00:01
In this question, it is given that the population mean mu equals 9 .8 and standard deviation sigma equals 0 .8.
00:12
So the first question is that we have to find the distribution of x, that is, x follows normal distribution with mean mu and standard deviation sigma implies that x follows normal distribution with mean.
00:30
8 and standard deviation 0 .8.
00:35
So this is the answer for the first question.
00:41
In the second question we have to find the probability of 9 .7 less than x less than 11 .2.
00:51
So this is equals probability of 9 .7 minus 9 .8 divided by 0 .8 less than x minus 9 .2.
01:02
Mu divided by sigma less than 11 .2 minus 9 .8 divided by 0 .8.
01:11
So this is equals probability of minus 0 .125 less than z less than 1 .75.
01:21
So this is equals probability of z less than 1 .75 minus probability of z less than minus 0 .125.
01:32
So using the standard normal table, we can find these probabilities, that is for alpha equals 0 .05 and for z value 1 .7, we will get the probability of z less than minus 1 .75 .5 and that is 0 .9599...