Harry asked a sample of 4 people how many siblings they had. Here are their responses:
1 answer:
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Given:
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