Answer: 191
Step-by-step explanation:
Formula to find the minimum sample size required to estimate a population proportion or percentage:

, where
= proportion estimated by prior study.
E= Margin of error.
z* = Critical z-value.
Given : Confidence level = 95%
Critical value for 95% confidence = z*=1.96

E= 7%= 0.07
Then, 


Hence, the minimum sample size required=191
Answer: 90 Earth years.
Step-by-step explanation:
Analizing the information provided in the exercise, you need to find the Least Common Multiple (LCM) of the given numbers.
You can follow these steps:
1. You must descompose 6, 9, 15 and 18 into their prime factors:

2. Finally, you need to choose the commons and non commons with their greatest exponents and multiply them. Then you get:

Therefore, it will take 90 Earth years for them to all line up.
Answer:
18,480
Step-by-step explanation:
you would fine how much she put in the bank in the first place!
250,000-96,000=154,000
Then you would do 154,000*0.02 to find how much interest is charged per month.
154,000*0.02=3080
Finally, you would multiply 3080 by 6 {because you need to account for all of the months}.
3080*6=18,480