In: Statistics and Probability
Suppose the mean starting salary for nurses is $67,276
nationally. The standard deviation is approximately $10,410....
Suppose the mean starting salary for nurses is $67,276
nationally. The standard deviation is approximately $10,410. The
starting salary is not normally distributed but it is mound shaped.
A sample of 47 starting salaries for nurses is taken.
State the random variable.
- The mean starting salary of a nurse.
- The standard deviation of starting salaries of nurses.
- Starting salary for a nurse.
What is the mean of the sample mean?
μx̄ =
What is the standard deviation of the sample mean? Round to two
decimal places.
σx̄ =
What is the shape of the sampling distribution of the sample
mean? Why?
- You can't say anything about the sampling distribution of the
sample mean, since the population of the random variable is not
normally distributed and the sample size is greater than 30.
- You can say the sampling distribution of the sample mean is
normally distributed since the sample size is greater than 30.
- You can say the sampling distribution of the sample mean is not
normally distributed since the sample size is greater than 30.
Find the probability that the sample mean is more than $75,000.
Round to four decimal places.
P(x̄ > 75000) =
Find the probability that the sample mean is less than $57,000.
Round to four decimal places.
P(x̄ < 57000)=
If you did find a sample mean of more than $75,000 would you
find that unusual? What could you conclude?
- It is not unusual to find a sample mean more than $75,000,
since the probability is less than 5%. If you find a sample mean
more than $75,000, then it may indicate that the population mean
has not changed.
- It is unusual to find a sample mean more than $75,000, since
the probability is at least 5%. If you find a sample mean more than
$75,000, then it may indicate that the population mean has
changed.
- It is not unusual to find a sample mean more than $75,000,
since the probability is at least 5%. If you find a sample mean
more than $75,000, then it may indicate that the population mean
has not changed.
- It is unusual to find a sample mean more than $75,000, since
the probability is less than 5%. If you find a sample mean more
than $75,000, then it may indicate that the population mean has
changed.