Question
The waiting time (in minutes) at the cashier of two supermarket
chains with different cashier systems is compared. The following
statistical test was performed:
Two Sample ttest
data: Waiting by Supermarket
t = 4.1777, df = 108, pvalue = 2.996e05
alternative hypothesis: true difference in means between group Sparag and group Consumo is greater than 0
95 percent confidence interval:
1.241878 Inf
sample estimates:
mean in group Sparag mean in group Consumo
5.419987 3.360063
Which of the following statements are correct? (Significance level 5%)

The absolute value of the test statistic is larger than 1.96.

A onesided alternative was tested.

The pvalue is larger than 0.05.

The test shows that the waiting time is longer at Sparag than at Consumo.

The test shows that the waiting time is shorter at Sparag than at Consumo.
Solution

True. The absolute value of the test statistic is equal to 4.178.

True. The test aims at showing that the difference of means is larger than 0.

False. The pvalue is equal to 3e05.

True. The test result is significant ($p < 0.05$) and hence the alternative is shown that the difference of means is larger than 0.

False. The test aims at showing that the waiting time at Sparag is longer than at Consumo.