Answer:
Step-by-step explanation:
If we assume that the number of arrivals is normally distributed and we don't know the population standard deviation, we can calculated a 95% confidence interval to estimate the mean value as:
where x' is the population mean value, x is the sample mean value, s is the sample standard deviation, n is the size of the sample, is equal to 0.05 (it is calculated as: 1 - 0.95) and is the t value with n-1 degrees of freedom that let a probability of on the right tail.
So, replacing the mean of the sample by 49, the standard deviation of the sample by 17.38, n by 10 and by 2.2621 we get:
Finally, the interval values that she get is: