00:01
Hi, i'm david and i'm here to help you unseen your question.
00:03
Now let me bring up your question here.
00:06
In the question here we are going to discuss about the competence interval for the mean.
00:12
Let me remind you that the confidence interval for the mule, it will be the x power plus or minus the z and 4 over 2 time with the sigma the vulnerable square into the n.
00:25
In the question here we need to find the competence interval with the n equal to the n 20 and we're given the same of mean x -par equal to the 123 .3 and we're given the standard division population standard division equal to the sixth and the question asked me to find the 95 % confidence interval for the mean look at the formula we have given the x bar the sigma and the n the only quantity we need to find it will be the z and 4 over 2 and the 95 % confidence and 5 equals to the 5 % divided by 2 equal to the 2 .5 % which is equal to the 0 .025.
01:06
It will look up the z table, this value equal to the 1 .96.
01:10
Now with this information, we are ready to write down the 95 % confidence interval for the mean.
01:18
Based on this formula here, x -par equals 123 .3 plus and minus 1 .96, 10 -winded sigma, over square root 20.
01:29
If we compute the quantity on the right, we see 1 .96 times 6 divided square root to the 20, equal to the 2 .6 to 96.
01:46
I need to round the answer to the 2 decimal places, so that i found the meal will be between...