In: Statistics and Probability
Independent random samples from two regions in the same area gave the following chemical measurements (ppm). Assume the population distributions of the chemical are mound-shaped and symmetric for these two regions. Region I: , 1008 852 567 749 764 727 945 657 880 773 1023 1002 Region II: , 1070 750 879 836 711 1070 706 866 608 892 891 965 998 1089 852 443 Let be the population mean for and be the population mean for Find a 90% confidence interval for
Values ( X ) | Values ( Y ) | |||
1008 | 32070.8283 | 1070 | 47687.6406 | |
852 | 532.8387 | 750 | 10327.6406 | |
567 | 68600.3577 | 879 | 749.3906 | |
749 | 6386.6789 | 836 | 244.1406 | |
764 | 4214.1779 | 711 | 19775.3906 | |
727 | 10387.0137 | 1070 | 47687.6406 | |
945 | 13475.3325 | 706 | 21206.6406 | |
657 | 29555.3517 | 866 | 206.6406 | |
880 | 2609.5035 | 608 | 59353.1406 | |
773 | 3126.6773 | 892 | 1630.1406 | |
1023 | 37668.3273 | 891 | 1550.3906 | |
1002 | 29957.8287 | 965 | 12853.8906 | |
998 | 21425.6406 | |||
1089 | 56346.8906 | |||
852 | 0.1406 | |||
443 | 166974.39 | |||
Total | 9947 | 238584.9162 | 13626 | 468019.7496 |
Mean
Standard deviation
Mean
Standard deviation
Confidence interval :-
DF = 25
Lower Limit =
Lower Limit = -127.4153
Upper Limit =
Upper Limit = 81.9987
90% Confidence interval is ( -127.4153 , 81.9987 )