00:01
In this question, we have been told in a survey conducted to determine, among other things, the cost of vacation.
00:08
Let assume that 64 individuals were randomly sampled.
00:13
Now, each person was asked about his or her most recent vacation and the cost involved.
00:21
So here the sample size is 64 and then if we look into the asked value in the problem, we can say we have been told to calculate.
00:30
Calculate the 95 percentage confidence, the average cost of all vacations and standard deviation is given as $400.
00:39
So here we have assumed that let sample mean equals x bar.
00:44
Now let us see how we can solve this problem further.
00:49
So we can firstly say that let us compute the alpha value.
00:54
So alpha value that is level of significance value will be equals to 1 minus 0 .95.
01:00
So, this will come about 0 .05.
01:03
So alpha value is this much, right? now here we can write alpha over 2 value.
01:08
So this will be equal to 0 .025.
01:12
So we can say that required probability will be equals to, that is now we are going to calculate the p value.
01:24
So we can say that required probability is equals to 1 minus alpha over 2.
01:31
That will come about 0 .975.
01:36
So, let us find the value of z alpha over 2.
01:39
And we have the information that probability of z greater than z alpha over 2 is equals to 0 .975...