b Construct a 99 confidence interval for the difference of the proportions

# B construct a 99 confidence interval for the

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b. Construct a 99% confidence interval for the difference of the proportions, before and after the change, of members who would recommend the Bank to their family and friends. 3. A national retailer has completed an internal survey on its social media strategy. The key question in the survey is whether the stores managers think that the recently- launched social media strategy is effective. The following is the output of a statistical analysis of the data: Social Media Strategy is effectiveStore ManagersNoYesWest Region 15 Central Region 10 East Region 45 Based on this output, can the retailer conclude that the opinion of the store managers on the whether the recently-launched social media strategy is effective is dependent on which region they belong to? Use a chi square test and a level of significance of 0.05. (4 points) 35 28 50
BUSI 1013: S TATISTICS FOR B USINESS 12 Social Media Strategy is effective Store Managers No Yes West Region 15 35 Central Region 10 28 East Region 45 50 50 38 95 70 113 183 Expected 19.13 30.87 14.54 23.46 36.34 58.66 Difference Square/Expected 0.890 0.551 1.415 0.877 2.064 1.279 Chi Square Statistic = 7.076 Since chi square statistic=7.076 >5.991, we reject H 0 and conclude that the recently-launched social media strategy is effective is dependent on which region they belong to 4. Use the data in BUSI1013 Bank Dataset.xlsx (from Unit 1 Exercise Question 2) to perform a statistical test on whether a customer would recommend the Bank to their
BUSI 1013: S TATISTICS FOR B USINESS 13 Recommend Before Gender Yes No Male 28 49 Female 22 53 family and friends before the change is dependent on the gender of the customer. ( 4 points ) 77 75 50 102 152 Expected 25.33 51.67 24.67 50.33 Difference Square/Expected 0.282 0.138 0.289 0.142 Test Statistic 0.851