The ages of ten employees at a small company are shown below. 30, 32, 35, 35, 38, 38, 38, 40, 40, 45

If the data set were expanded to include a new employee who is 20 years old, how would the mean of the data set change?

A) The mean decreases by 2 years.
B) The mean decreases by about I .6 years.
C) The mean increases by about 1.6 years.
D) The mean does not change.

On a certain portion of an experiment, a statistical test result yielded a p-value of 0.21. what can you conclude? 2(0.21) = 0.42 < 0.5; the test is not statistically significant. if the null hypothesis is true, one could expect to get a test statistic at least as extreme as that observed 21% of the time, so the test is not statistically significant. 0.21 > 0.05; the test is statistically significant. if the null hypothesis is true, one could expect to get a test statistic at least as extreme as that observed 79% of the time, so the test is not statistically significant. p = 1 - 0.21 = 0.79 > 0.05; the test is statistically significant.