A sample of a radioactive isotope had an initial mass of 560 mg in the year 1995 and decays exponentially over timeſ A measurement in the year 2002 found that the
sample's mass had decayed to 90 mg. What would be the expected mass of the
sample in the year 2012, to the nearest whole number?

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.