Statistics Iceland conducted a study to examine whether there was a difference between the food costs of households in the capital area and households in rural areas. Food expenses for 45 households in rural areas averaged ISK 2,800 per day, standard deviation ISK 270. Food expenses for 55 households in the capital area averaged ISK 2,100 per day, standard deviation ISK 190. a) What is the common standard deviation of the groups (Pooled standard deviation)? Submit an answer without decimals. b) What is the coefficient of Cohen's d? Use a common standard deviation in the formula. Submit an answer without decimals.