00:01
Hello students in this question, you need to test h naught mu 1 is equal to mu 2 versus h a mu 1 is not equal to mu 2.
00:12
So, here the test statistic is t is equal to x 1 bar minus x 2 bar divided by square root of s 1 square divided by n 1 plus s 2 square divided by n 2.
00:24
So, now, substituting the values here 1 0 1 2 minus 944 .9 divided by square root of 34 .7 square divided by 9 plus 78 .2 square divided by 9.
00:42
So, that is equal to 67 .1 divided by 28 .5177 and that is equal to 2 .3529 and here we have the degrees of freedom n 1 plus n 2 minus 2.
01:01
So, that is equal to 16 and alpha 0 .01.
01:05
So, here the t critical value is plus or minus 2 .9208.
01:11
That means, we reject we reject h naught if mod t value is greater than 2 .9208.
01:22
So, here our calculated value is 2 .3529 which is less than the t critical value.
01:34
Therefore, we fail to reject fail to reject the null hypothesis.
01:45
That means, there is no significance significance difference in melting points and next for the question b we need to test h naught u d is equal to 0 versus h a u d is not equal to 0.
02:14
So, here the test statistic is t is equal to d bar divided by s t divided by root n.
02:21
So, now, substituting the values 67 .1 divided by 89 divided by root 9...