Answer: B) 18
Step-by-step explanation:
The degree of freedom for Standard error or df(Residual) is the sample size minus the number of estimated parameters ,.
df= n - p , where n= sample size , p = number of parameters.
According to the given problem , we have
Sample size : n=20
Number of parameters (x and y ): p= 2
Then, the df value for the standard error of estimate will be :
df= n-p =20-2=18
Thus , the df value for the standard error of estimate is 18 .
Hence, the correct answer is B) 18 .
Answer:
x=7.5
y=1.5
Step-by-step explanation:

subtract x from both sides




combine like terms

subtract 1.8 from both sides

divide both sides by 0.3
x=7.5


y=1.5
Answer:
5m/s;
6 seconds
Step-by-step explanation:
Given the following :
Initial position = 30 m below
He climbed at a constant rate, and was 7.5 m below after 4.5 s.
Distance climbed or covered in 4.5 seconds :
(Initial position - current position)
(30 - 7. 5)m = 22.5 meters
Using the relation:
Speed = distance covered / time taken
Therefore,
Shota's speed = 22.5m / 4.5s = 5m/s
Time taken to reach edge of volcano :
Distance left to cover = 7.5m
Speed = 5m/s
Time required to cover remaining distance :
= distance / speed
= (7.5m ÷ 5m/s) = 1.5s
Total time to reach edge :
(4.5 + 1.5)s = 6 seconds