The following random sample from a population whose values were normally distributed was collected.10 8 11 11The 95% confidence interval for μ is:a. 8.00 to 10.00b. 7.75 to 12.25c. 9.75 to 10.75d. 8.52 to 10.98

B

Step-by-step explanation:

First to find the sample mean

Xbar= summation x/n= 40/4= 10

The sample standard deviation is:

S= √summation(x-xbar)²/ n-1

=√6/3= 1.4142

The degrees of freedom

df= N-1= 4-1= 3

For 95% confidence level, critical value of t

t= 3.182

The 95% confidence interval is:

=Xbar plus or minus t' *8/√n

= 10 plus or minus 3.182(1.4142/√4)

= 10plus or minus 2.25

So 7.75 or 12.25

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.

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step-by-step explanation: