I'll go slow:





Answer: B rational and equal to 0.
Answer:
A sample of 997 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of
.
The margin of error is of:

A previous study indicates that the proportion of left-handed golfers is 8%.
This means that 
98% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How large a sample is needed in order to be 98% confident that the sample proportion will not differ from the true proportion by more than 2%?
This is n for which M = 0.02. So






Rounding up:
A sample of 997 is needed.
Answer:
8.31 weeks
Step-by-step explanation:
Given that the cost of one share of Apple stock, C=$120
Rate is the increment of the stock value, R= 5%/week=0.05 / week.
Assuming that after t week, the stock has been sold for $180.
Since the stock value increased at 5% every week, so, the interest is compounded weekly, so


[taking log both sides]
weeks
Hence, after 8.31 weeks the stock has been sold for $180.
Answer:
2
Step-by-step explanation: