Answer:

Step-by-step explanation:
Given

Required
Determine the roots
To get the root of the function, then f(b) must be 0;
i.e. f(b) = 0
So, the expression becomes

Add 75 to both sides


Take square roots of both sides


Reorder

Expand 75 as a product of 25 and 3

Split the expression




The options are not clear enough; however the roots of the equation are 
Answer:
Coefficient is equal to 12
k<2(3.5) or simplified k<7
Answer:
For this case the confidence interval is given by :

Step-by-step explanation:
Data provided
represent the sample mean for the fuel efficiencies
population mean
s=2.51 represent the sample standard deviation
n=601 represent the sample size
Confidence interval
The formula for the confidence interval of the true mean is given by:
(1)
The degrees of freedom for this case is given by:
The Confidence level for this case is 0.95 or 95%, and the significance level
and
and the critical value is given by
Replcing into the formula for the confidence interval is given by:
For this case the confidence interval is given by :

Hey there!
![\left[\begin{array}{ccc}\boxed{\boxed{ \frac{6}{4}}} \end{array}\right] = \left[\begin{array}{ccc}\boxed{\boxed{150}}\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Cboxed%7B%5Cboxed%7B%20%5Cfrac%7B6%7D%7B4%7D%7D%7D%20%5Cend%7Barray%7D%5Cright%5D%20%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Cboxed%7B%5Cboxed%7B150%7D%7D%5Cend%7Barray%7D%5Cright%5D%20)
All I did was to multiply each side by 100 which then go me this!
Hope this helps!