This sequence is represented as:
a(n+1) = 5 + 11n
So for 19th term, a(19) = 5 + 11*(19-1) = 203
A. f(1)=5 (as defined on the second line, x=1) TRUE because f(1)=5
B. f(5)=5^2=25 (as defined on third line, x>1) FALSE because f(5) ≠ 1
C. f(-2)=2(-2)=-4 (as defined on first line, x<1) FALSE because f(-2) ≠ 4
D. f(2)=2^2=4 (as defined on third line, x>1) TRUE because f(2)=4
Answer:
1) 1.8
2) 1.7
Step-by-step explanation:
(for part A)
Mean: 3 + 5 + 6 + 3 + 2 + 2 + 1 + 0 + 0 + 4 + 7 + 4 + 5 + 5 + 6 = 53/15 = 3.5
3.5 - 3 = 0.5
3.5 - 5 = 1.5
3.5 - 6 = 2.5
3.5 - 3 = 0.5
3.5 - 2 = 1.5
3.5 - 2 = 1.5
3.5 - 1 = 2.5
3.5 - 0 = 3.5
3.5 - 0 = 3.5
3.5 - 4 = 0.5
3.5 - 7 = 3.5
3.5 - 4 = 0.5
3.5 - 5 = 1.5
3.5 - 5 = 1.5
3.5 - 6 = 2.5
mean absolute deviation: 0.5 + 1.5 + 2.5 + 0.5 + 1.5 + 1.5 + 2.5 + 3.5 + 3.5 + 0.5 + 3.5 + 0.5 + 1.5 + 1.5 + 2.5 = 27.5/15 = 1.8
(part B)
Mean: -3 + -2 + -1 + 0 + 1 + 2 + 3 = 0/7 = 0
0 - (-3) = 3
0 - (-2) = 2
0 - (-1) = 1
0 - 0 = 0
0 - 1 = 1
0 - 2 = 2
0 - 3 = 3
mean absolute deviation: 3 + 2 + 1 + 0 + 1 + 2 + 3 = 12/7 = 1.7
a. To find the least squares regression equation for a group of (x,y) points:
Step 1: For each point(x,y), we need to calculate x² and xy first.
Step 2: Sum all x, y, x² and xy, which gives us Σx, Σy, Σx² and Σxy
Step 3: Calculate Slope m: m = (NΣxy − Σx Σy)/ N(Σx²) − (Σx)² , here N is the number of data.
Step 4: Calculate Intercept b: b = Σy − m(Σx)/ N
Step 5: Assemble the equation as y= mx+b
Here, we have ∑x = 120, ∑y= 1379, ∑x²= 919.5, ∑xy= 10466 and N= 16
So, m= (NΣxy − Σx Σy)/ N(Σx²) − (Σx)²
= 
= 
= 
= 6.33
and b = Σy − m(Σx)/ N
= 
= 
= 
= 38.71
So, the least squares regression equation is : y= mx+b ⇒ y= 6.33x +38.71
b. When x= 8, then y= (6.33×8)+38.71 = 50.64 + 38.71 =89.35
The approximate test score of a student who sleeps an average of 8 h a night is 89.35%