From 1990 through 1999, the female population F and the male population M of the United States (in thousands) is modeled by the following equations, where n is the number of years since 1990. Source: U. S.
Census Bureau

F =1247n +126,971 M= 1252n +120,741

a) Find an equation that models the total population T in thousands of the United States for this time period.
b) If this trend continues, what will the population of the United States be in 2010?
3. The measures of two sides of a triangle are given. If P is the perimeter, find the measure of the third side.

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.