Asample of 81 was taken from a population with a standard deviation of 45 kilograms. if the sample mean was 112 kilograms, the mean of any other sample of 81 will be within what range 99.7% of the time? a. 97 kilograms to 127 kilograms b. 102 kilograms to 122 kilograms c. 92 kilograms to 132 kilograms d. 107 kilograms to 117 kilograms

b.my answer is b.

brainliest

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.