When i calculated it , it says 993.813
.91 times 4000=3640 people prefer Pedro’s
4000-3640= 360 people prefer other brands
Life life life man woman child
Stop making jokes about this life
Said a person with a hat
B because you already know number of cookies eaten, you dont know if the total was 12 cookies because you dont know how many days so, if you dont know how many days then y would be the number of days... Good Luck
Answer:
a) 
b) n = 381
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 zscore that has a pvalue of
.
The margin of error is:

90% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
a. Assume that nothing is known about the percentage of computers with new operating systems. n = ?
When we do not know the proportion, we use
, which is when we are going to need the largest sample size.
The sample size is n when M = 0.01.






b. Assume that a recent survey suggests that 99% of computers use a new operating system. n = ?
Now we have that
. So






Rouding up
n = 381