21.9089 is the geometric mean..
Answer:
20
Step-by-step explanation:
The Function having highest Degree of Four given here is :

As the given function has highest degree of four, it has maximum of four roots.
As complex and Irrational root occur in pairs, so There are many possibilities
1. Two Complex or Irrational + Two Real
2. Four real roots
3.All roots are complex or irrational
By looking at the options described below, it means it has four real roots.
It will cut X axis at four points.
With the help of Desmos you can directly find the solution of this problem, but without desmos Graphing, we first have to check by Taking different points on the curve whether graph of function described here is correct or not, i.e by method of increasing and decreasing formula of a function.The method to check is
If there are two points on the curve i.e 
1.
Increasing Function.
2.
Decreasing Function.
Option (4) is true .
Answer:
H0 : μEng = μBio
H1: μEng ≠ μBio
Step-by-step explanation:
μEng = Engineering average gpa
μBio = Biology average gpa
To test for difference between two sample means , in this case grade point average of biology majors and Engineering major.
Null hypothesis is the initial truth, which is that ; there is no difference in the mean grade point average of both biology and engineering majors
H0 : μEng = μBio
The Alternative hypothesis is the opposite of the null, which is stated has ; there is difference between the average GPA of both Engineering and Biology majors
H1: μEng ≠ μBio