Idon't understand how to do this can someone

According to the normal model, what percent of receivers would you expect to gain fewer yards than 2 standard deviations below the mean number of yards

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?

How many real-number solutions does the equation have? -4x^2 + 10x + 6 = 0 a. no solutions b. two solutions c. infinitely many solutions d. one solution