HELP PLEASE!!

A multiple-choice test has 15 questions. Each question has 4 possible responses, so the
probability is 0.25 for guessing right. Suppose you randomly guess for all 15 questions.
Let X = the number of correct responses.

1. Calculate the mean of X. Interpret the mean in context.

2. Calculate the standard deviation of X. Interpret the mean in context.

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.

ur right ive taken the test

step-by-step explanation:

the answer is "add 2y and y"

step-by-step explanation:

you need to collect the like terms first.