The model a = 0.25t + 29 represents the median age a of females in the united states as a function of time t (in years since 1970). a. predict the median age of females in 2007 to the nearest tenth. 2007 is years after 1970, so a = 0.25( ) + 29 = b. predict the median age of females in 2018 to the nearest tenth. 2018 is years after 1970, so a = 0.25( ) + 29 =

a. 38.3

b. 41.0

Step-by-step explanation:

We have been given the linear model;

a = 0.25t + 29

where a represents the median age of females in the United States and t the number of years since 1970

a.

We are required to predict the median age of females in 2007. The first step is to determine the number of years from 1970 to 2007 by finding the difference;

2007 - 1970 = 37

2007 is  thus 37 years after 1970.

The next step is to substitute t = 37 in the given linear model;

a = 0.25( 37) + 29 = 38.25

b.

We are required to predict the median age of females in 2018. The first step is to determine the number of years from 1970 to 2018 by finding the difference;

2018 - 1970 = 48

2018 is thus 48 years after 1970

The next step is to substitute t = 48 in the given linear model;

a = 0.25( 48) + 29 = 41

1/4 because there is 4 grades.