Answer:
A sample size of 1031 is required.
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 of:
37% of freshmen do not visit their counselors regularly.
This means that
98% confidence level
So , z is the value of Z that has a pvalue of , so .
You would like to be 98% confident that your estimate is within 3.5% of the true population proportion. How large of a sample size is required?
A sample size of n is required.
n is found when M = 0.035. So
Rounding up:
A sample size of 1031 is required.
Answer:
And the best option would be:
Step-by-step explanation:
We assume that the distribution for the random variable is:
For this case we want to calculate the following probability:
And we can use the normal standard distribution or excel and we got:
And the best option would be:
Answer:
a) 74.69
b) 0.08% probability that on a given day, 51 radioactive atoms decayed.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given time interval.
a. Find the mean number of radioactive atoms that decayed in a day.
27,263 atoms in 365 days. The mean is
b. Find the probability that on a given day, 51 radioactive atoms decayed.
This is P(X = 51).
0.08% probability that on a given day, 51 radioactive atoms decayed.