In a recent year, 77.8% of recorded music sales were full-length cds, 12.8% digital downloads, 3.8% singles, and the rest a mixture of other formats. a survey of college students and their recent music purchases indicated that out of 200 purchases, 48 were downloads, 135 were full-length cds, 10 were singles, and the rest fit into the "other" category. at the 0.05 level of significance is there sufficient evidence to conclude that at least one of the proportions differs from its original value?

step-by-step explanation:

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

the correct answers i think are b. and d.

give me brainliest if it is correct!

knlknlkkn

step-by-step explanation: