1.Two groups, A and B, consists of 100 subjects each, each with a disease. A serum is given to group A but not to group B (the control); otherwise the two groups are treated identically. It is found that in groups A and B, 75 and 65 persons, respectively, recover from the disease. Test the hypothesis that the serum helps to cure the disease, using a level of significance of 5% (0.05).

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?