A penny is tossed. We observe whether it lands heads up or tails up. Suppose the penny is a fair coin; that is, the probability of heads is one-half and the probability of tails is one-half. What does this mean?A) if I flip the coin many, many times, the proportion of heads will be approximately 1/2, and this proportion will tend to
get closer and closer to 1/2 as the number of tosses increases.
B) regardless of the number of flips, half will be heads and half tails.
C) every occurrence of a head must be balanced by a tail in one of the next two or three tosses.
D) all of the above.

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.