Is there a difference between health service workers and educational service workers in the amount of compensation employers pay them per hour? Suppose a random sample of seven health service workers is taken along with a random sample of eight educational service workers from different parts of the country. Each of their employers is interviewed and figures are obtained on the amount paid per hour for employee compensation for these workers. The data on the following page indicate total compensation per hour. Use a Mann$-$ Whitney U test to determine whether these two populations are different in employee compensation. $[$ Here $,$ p$-$value of $0\mathrm{.}0011,$ as this test is two tailed $,$ we double the table p$-$value, producing a final p$-$ value of $0\mathrm{.}0022.]$

Health Service Worker Educational Service Worker

$20\mathrm{.}1026\mathrm{.}19$

$19\mathrm{.}823\mathrm{.}88$

$22\mathrm{.}3625\mathrm{.}50$

$18\mathrm{.}7521\mathrm{.}64$

$21\mathrm{.}9024\mathrm{.}85$

$22\mathrm{.}9625\mathrm{.}30$

$20\mathrm{.}7524\mathrm{.}12$

$23\mathrm{.}45$