A random sample of 121 automobiles traveling on an interstate showed an average speed of 65 mph. From past information, it is known that the standard deviation of the population is 22 mph. The standard error of the mean is

2.

Step-by-step explanation:

Number of samples = 121

Average speed (sample mean) = 65mph

Population standard deviation = 22 mph

The standard error of the mean is:

Standard error of the mean(S.Em)

Standard error of the mean is the proportion of the population standard deviation and the square root of the sample size.

S.Em = standard deviation / √same size

S.Em = 22 / √121

S.Em = 22 / 11

S.Em = 2

the answer to the question is a  

it has the same slope and the same y-intercept.

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.