210-15x=y x represents the amount of times she goes, and y represents the amount of money after
Answer:
55.00
Step-by-step explanation:
Answer: 18
Step-by-step explanation:
The formula to find the minimum sample size is given by :_

, where
= population standard deviation.
z*= critical z-value.
E= Margin of error.
Given : 
E= ± 8
We know that critical value corresponding to 99% confidence level = z*=2.576 [Using z-table]
Then, the required sample size would be :


[Round to next integer.]
Hence, the required minimum sample size = 18