An urban community would like to show that the incidence of breast cancer is higher in their area than in a nearby rural area. (pcb levels were found to be higher in the soil of the urban community.) if it is found that 20 of 200 adult women in the urban community have breast cancer and 10 of 150 adult women in the rural community have breast cancer, can we conclude at the 0.05 level of significance that breast cancer is more prevalent in the urban community?