Use the following table to complete the following problems. The table shows the percentage of Americans under age 18 at time $t$.

$$\begin{array}{c|c} t & P(t) \\ \hline 1950 & 31.1 \\ 1960 & 35.7 \\ 1970 & 34.0 \\ 1980 & 28.0 \\ 1990 & 25.7 \\ 2000 & 25.7 \end{array}$$
A) Put the correct number in the Answer box. Which one of the following are the correct units for $P'(t)$.

1) people / year
2) % / year
3) $\mathrm{people}^2$ / year
4) year / %

B) Use the 6B answer boxes below to fill in the values for $P'(t)$ for the corresponding years (to three decimal places).

C) Pick the correct graph for P and P' (Put the correct number in the C answer boxes below)

1) 2) 3) 4)

D) Which of the following is a valid way to get more accurate values for $P'$ (put the correct number in the D answer box)
1) Find out $P(t)$ for mid Decade years
2) Eliminate every other year's data
3) Poll less people for the consensus

$A)$

$B-1950)$

$B-1960)$

$B-1970)$

$B-1980)$

$B-1990)$

$B-2000)$

$C-P(T)$ graph)

$C-P'(T)$ graph)

$D)$