statistic
giumag
Ch.10testclasswork2.xlsx9.1 Z test for the Mean
| Z test for the Mean | Problem: | |
| You are the manager for Oxford Cereals. Among other responsibilities | ||
| Data | , you are responsible for monitoring the amount in each cereal box. | |
| Null Hypothesis | Company specifications requrie a mean weight of 368 grams per box. | |
| Level of Significance | 0.05 | You select a random sample size of 25 ceral boxes. The standard deviation of the cereal |
| Population Standard Deviation | filing process is 15 grams and we found the sample mean to be 372.5 grams | |
| sample size | ||
| sample mean | ||
| Intermediate Calculations | ||
| Standard Error of the Mean | B6/SQRT(B7) | |
| Z Test Statistic | (B8-B4)/B11 | |
| Two- Tail Test | ||
| Lower Critical Value | NORMSINV(B5/2) | |
| Upper Critical value | NORMSINV(1-B5/2) | |
| p-value | 2*(1-NORMSDIST(ABS(B12))) | |
| IF(B17<B5, "reject null hypothesis", "Do not reject null hypothesis") |
10.1 Comparing the Mean
| Local | Chain | Pooled Variance t Test fro Difference in Two Means | |
| 16.8 | 22 | assumed equal population variances | |
| 11.7 | 15.2 | Data | |
| 15.6 | 18.7 | Hypothesized difference | |
| 16.7 | 15.6 | Level of Significance | |
| 17.5 | 20.8 | Population 1 | |
| 18.1 | 19.5 | sample size | COUNT(A2:A11) |
| 14.1 | 17 | sample mean | AVERAGE(A2:A11) |
| 21.8 | 19.5 | sample standard deviation | STDEV(A2:A11) |
| 13.9 | 16.5 | Population 2 | |
| 20.8 | 24 | sample size | COUNT(B2:B11) |
| sample mean | AVERAGE(B2:B11) | ||
| sample standard deviation | STDEV(B2:B11) | ||
| Intermediate Calculations | |||
| POP1 degrees of freedom | E7-1 | ||
| POP2 degrees of freedom | E11-1 | ||
| Total degrees of Freedom | E16+E17 | ||
| Pooled variance | ((E16*E9^2)+(E17*E13^2))/E18 | ||
| Standard Error | SQRT(E19*(1/E7+1/E11)) | ||
| Difference in sample Means | E8-E12 | ||
| t test Statistic | (E21-E4)/E20 | ||
| TWO TAIL TEST | |||
| Lower Tail test | ERROR:#NUM! | ||
| Upper Tail test | T.INV.2T(E5, E18) | ||
| p-value | T.DIST.2T(ABS(E22), E18) | ||
| Do not reject the null Hypothesis | IF(E27<E5, "Reject the Null Hypothesis", "Do not reject the null Hypothesis") |
