Answer:
Only the mean increased.
Step-by-step explanation:
The mean is the total divided by the number of scores, and since adding 21 will increase the total score significantly, the mean increases.
The median is still 7.
The coefficient for the first y is 1. Second y is 4. Third y is -3.
Answer:
Y= 1/3x-15
Step-by-step explanation:
-6=-3(-3)+b
-6= 9+b
subtract 9 on both sides
b= -15
Y= 1/3x-15
because its perpendicular the -3x become positive and reciprocal
Hint: 423 = (40 + 2)3; therefore, x = 40 and y = 2.
Answer: The answer is (D) 
Step-by-step explanation: We are to select the correct function which represents exponential decay.
We know that an exponential decay is represented by the function with base less than 1.
For example, if we consider the following exponential function:

then f(x) will show exponential growth if b > 1 and exponential decay is b < 1.
Among the given functions,
represents exponential decay, because the base is 0.66, which is less than 1.
Thus, (D)
is the correct option.
The graph of this resultant function is attached, which clearly represents exponential decay.