00:01
Hello student here we have to construct a 95 % confidence level for me with sample standard deviation is equal to 1 .15 and with sample size n is equal to 75 and with sample mean x bar is equal to 6 .97.
00:22
So here first alpha is equal to 1 minus confidence level that is 1 minus 0 .95 which is equal to 0 .05 and here decrease of freedom is equal to n minus 1 that is 74 and here p is equal to 1 minus alpha by 2 that is 1 minus 0 .05 divided by 2 which is equal to 0 .975.
00:48
Now here formula for calculating confidence interval here confidence interval is equal to x bar plus minus 0 .975 into s upon square root of now here.
01:07
We substitute the value.
01:08
So here x bar is equal to 6 .97 plus minus 1 .99 into 1 .5 divided by square root of 75 we are solving it will give us the value which is equal to 6 .97 plus minus 0 .13.
01:34
I'm simultaneously subtracting and adding 0 .13.
01:37
It will gives confidence interval for me which is equal to 6 .71 less than you less than 7 .03.
01:51
Now here in the next bit we have given that 95 % confidence interval is here.
02:01
We have given 95 % confidence interval which is equal to 3 .2 less than 2 less than 3 .8.
02:11
So here we interpret it as we are 95 % sure that average in somewhere in the interval is the correct answer...