A drapery store manager was interested in determining whether a new employee can install vertical blinds faster than an employee who has been with the company for two years. Assume that two populations are normal. The manager takes independent samples of $10$ vertical blind installations of each of the two employees and computes the following information.

New Employee Veteran Employee

Sample Size $99$

Sample Mean $15\mathrm{.}218\mathrm{.}1$

Sample Standard Deviation $1\mathrm{.}51\mathrm{.}1$

What is the value of the test statistic for testing

vs$.$

$?$