he percentage of female high school graduates who enrolled in college is given in the table below.

YearCollege Enrollment Percentages for Females197025.5198030.3199038.3200045.6201050.5

Letx

xrepresent time (in years) since 1970, and lety

yrepresent the corresponding percentage of female high school graduates who enrolled in college.

Find the cubic regression model

y=F(x)=ax

3

+bx

2

+cx+d

y=F(x)=ax3+bx2+cx+d,

where

ais rounded to 6 decimal places,b

bis rounded to 4 decimal places,c

cis rounded to 3 decimal places, andd

dis rounded to 1 decimal place.

Use the model to predict instantaneous rate of change of the percentage of female high school graduates in 2013.Round to the nearest hundredth (2 decimal places).

% per year