Answer:
Mean = 30
standard Deviation = 2.74
Step-by-step explanation:
Formula
mean = np
Standard Deviation = 
from the question = 40
P = 75% or 0.75
q = 1 - p = 1 - 75% or 1 - 0.75
To find mean
mean = 40 x 0.75
= 30
For Standard Deviation (SD)
Standard Deviation =
= 
= 
:. Standard Deviation = 2.74
The square root of a number is multiplying that number by its self so like 2² which is 2 squared. the answer would be 2 x 2 = 6 hope this helps!
Answer:
-29
Step-by-step explanation:
-ab-ac
= -(-6)(2/3)-(-6)(-5.5)
=4-33
= -29