00:01
So our question says iq scores are normally distributed with a mean of 100 and a standard deviation of 15.
00:06
A researcher desired to build a 95 % confidence on the iq score.
00:11
So find a sample size that the researcher needs to achieve a minimum error of 2 iq units.
00:18
So our population mean meal.
00:20
So for question 1, our meal is equals to 100.
00:23
Sigma is equal to 15.
00:25
We need the sample size, which is unknown.
00:27
Confidence level, we have that to be 95.
00:30
Percent and margin of error is equal to two.
00:33
Now the formula for the confidence for the margin of error rather is m .e is equal to the critical value times sigma divided by the square out of n.
00:43
The critical value is all that we need and this is dependent on the type of distribution that defines our data sets.
00:50
Since we have the value of the population standard division, we can definitely say that our data set is normally distributed.
00:57
Hence that means our critical value is going to be a this score at 95 % confidence level it means that our alpha level is equals to 5%.
01:05
So that is 0 .05...