Question

Six months after settling the strike, H&H worker union sued the firm for reneging on its promise to increase employee salaries. The union hired an independent consulting firm that randomly selected four H&H Bagels stores in different locations and asked the employees about their salaries before and after the strike. The mean salaries of all employees in each store before and after the strike are shown in the table below:

NYC H&H Bagels Store Location	Mean Hourly Salary Before the Strike	Mean Hourly Salary After the Strike
Brooklyn	12.60	12.80
Queens	10.40	10.50
Bronx	10.00	10.30
Manhattan	15.20	15.60

If you were the independent consultant, would you conclude that H&H management fulfilled their promise to increase the employee salaries at a = 0.01 significance level? Support this conclusion using five-step hypothesis testing procedure.

Answer 1

Paired T-Test and CI: Before the Strike, Salary After the Strike

Descriptive Statistics

Sample	N	Mean	StDev	SE Mean
Before the Strike	4	12.05	2.39	1.20
Salary After the Strike	4	12.30	2.48	1.24

Estimation for Paired Difference

Mean	StDev	SE Mean	99% Upper Bound for μ_difference
-0.2500	0.1291	0.0645	0.0431

µ_difference: mean of (Before the Strike - Salary After the Strike)

Test

Null hypothesis	H₀: μ_difference = 0
Alternative hypothesis	H₁: μ_difference < 0

T-Value	P-Value
-3.87	0.015

since p-value is greater than 0.01 we fail to reject null hypothesis and we conclude that H&H management not fulfilled their promise to increase the employee salaries at a = 0.01 significance level