Answer:
--- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
<u>Start by calculating the mean</u>
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.
So, we have:
Next, calculate the variance using the following formula:
i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:
Lastly, take the square root of the variance to get the standard deviation
--- approximated
<em>Hence, the standard deviation is approximately 11.28</em>
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
Answer is 12
Reason
Combine like terms
3x + 99 x = 1224
102x = 1224
Now solve for x
Divide both sides by 102
x= 12
Answer: Domain = 
Range = 
Step-by-step explanation:
Here, the given function,
Since log( negative number ) = not defined
Also,
Hence, f(x) is defined if x - 1 > 0
⇒ x > 1
Thus, f(x) is defined for all the values that are greater than 1,
⇒ Domain of f(x) = All real number greater than 1,
= 
Now, for the interval ,
f(x) can be any real number.
Thus, the range of the given function =
Answer:
A. The stepwise selection procedure uses Adjusted R-square as the "best" model criterion.
Step-by-step explanation:
Stepwise regression is a model which uses variables in step by step manner. The procedure involves removal or inclusion of independent variables one by one. It adds the most significant independent variable and removes the less significant independent variable. Usually stepwise selection uses R-square or Mallows Cp for picking the best fit.
90 miles driving at 45 mph for 2 hours
