Answer:
The answer is a and d
Step-by-step explanation:
Answer:
y=1/2sin(1/2x)
Step-by-step explanation:
because i use my brain to count
Mean = (19 + 20 + 21 + 22 + 23)/5 = 105/5 = 21
x x - mean (x - mean)^2
19 -2 4
20 -1 1
21 0 0
22 1 1
23 2 4
Sum = 10
Standard deviation = sqrt(sum(x - mean)^2 /n) = sqrt(10/5) = sqrt(2)