Here is my stats question, and an answer that I purchased from this website by another tutor. Q1 part b is not clear to me though. How did they get to this part? :

Thus Z=3.3226

The tabulated value at 2.5 % LOS is 1.9596

I understand how to get the Z-score, but not the tabulated value. Where do you get the 2.5% and 1.9596 values? I don't really understand how to use a t-table, if that's what you need.

Thank you!

Questions:

https://www.coursehero.com/tutors-problems/Statistics-and-Probability/7312535-Please-show-as-many-steps-as-possible/

A1)

The 98% Ci for the difference between population means is :

Where,

Using all the values , the confidence interval is given by:

(0.006, 0.034)

b)

Let denote the mean reaction time of non players of video games in the population and denote the mean reaction time of players of video games in the population.

Null hypothesis, Ho: =

Alternative hypothesis, H1: >

The test statistic :Z=

Where,

Thus Z=3.3226

The tabulated value at 2.5 % LOS is 1.9596

Thus HO is rejected as the calculated value is greater than tabulated value. Thus the researcher can conclude his hypothesis.