Answer: Observational study
Step-by-step explanation: I just took the test
Given :
p = 0.68
margin of error, E = 0.1
99% confident interval
alpha, α = 1 - 0.99
= 0.01

∴
(z-critical value)
Sample size = 


= 144.37
= 145 (rounded off)
Therefore, there are 145 businesses does she need to sample to meet this criteria.
Answer: The correct answer is B because 0.7x=210, x=300
Step-by-step explanation:
210= 70% of the total distance to his grandfather's house, lets take that total distance for x.
So if:
210=0.7x
x=210/0.7
x=300