00:01
Hello students here for the question number a they given that mu is equal to 10 237 and the x bar is equal to 10798 sigma is equal to 1560 then n is equal to 150 then the given level of significance alpha is 0 .05 now we want to frame the hypothesis mu is equal to 10337 and on the alternative hypothesis h -alpha mu not equal to 10 -337.
00:40
The formula for calculating the test statistic is that x bar minus mu divided by sigma by square root of n.
00:47
Now substitute the known values.
00:49
We get 10798 minus 10337 divided by 1560 divided by 1560 divided by square root of 150.
00:59
We get our z value as 3 .619.
01:03
Then here the p value for this test is 0 .003, which is less than the alpha 0 .05.
01:14
So here we reject the null hypothesis h0.
01:27
Then for the subpart b, we've given that x par is equal to 10798 and the sigma is 1560, is equal to 150 then the given confidence interval is 95 percentage here we need to find the confidence interval the formula for calculating the confidence interval is x bar plus r minus z alpha by 2 into sigma by square root of n now substitute the known values here we get z alpha by 2 which is z 0 .05 by 2 we get 1 .96 that is 10798 plus or minus 1 .96 into 1560 divided by square root of 150.
02:25
By simplifying this we get 10798 plus or minus 249 .6474.
02:34
Therefore here we get 10 -548 .35 and 11047 .65.
02:44
To two decimal places here we get.
02:48
Here the given mu is 10 -337...