Researchers are interested in estimating the mean change in student scores on their second attempt at the GRE Quantitative exam. History indicates the change in score is normally distributed with a standard deviation of 50. How large a sample should the researchers take they want to be with in 2 units of the true value with 95% confidence

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x