The city council of pine bluffs is considering increasing the number of police in an effort to reduce crime. before making a final decision, the council asked the chief of police to survey other cities of similar size to determine the relationship between the number of police and the number of crimes reported. the chief gathered the following sample information.

city police number of crimes city police number of crimes
oxford 15 17 holgate 17 7
starksville17 13 carey 12 21
danville 25 5 whistler 11 19
athens 27 7 woodville 22 6

a)determine the regression equation. (round your answers to 4 decimal places. negative amounts should be indicated by a minus sign.)
b)estimate the number of crimes for a city with 20 police officers. (round your answer to the nearest whole number.)