# statistics

posted by .

ER promises you will be seen in 10 minutes. the standard deviation is 2 minutes. chance someone will wait more than 13 minutes.

i don't know what to do without a population size or sample size

• statistics -

Try z-scores.

z = (x - mean)/sd

Once you have the z-score, check out a z-table for your probability. (Remember that the problem is looking for "more than 13 minutes" when you determine the probability.)

## Similar Questions

1. ### statistics

a study found that the means waiting time to see a physican at an outpatient clinic was 40 minutes with a standard deviation of 28 minutes. use excel to find each probability. a. what is the probability of more than an hours wait?
2. ### statistics

1. A random sample of size 49 is taken from a large population, measuring the time it takes to complete a driverâ€™s license examination. The sample mean was found to be 47 minutes, and the sample standard deviation 5.89 minutes. Construct …
3. ### Statistics

A study in Orlando, Florida claimed that the mean commute time for all employees working at Disney exceeds 40 minutes. This figure is higher than what was assumed in the past. The plan is to test this claim at a level of significance …
4. ### statistics

A study in Orlando, Florida claimed that the mean commute time for all employees working at Disney exceeds 40 minutes. This figure is higher than what was assumed in the past. The plan is to test this claim at a level of significance …
5. ### Statistics

A study in Orlando, Florida claimed that the mean commute time for all employees working at Disney exceeds 40 minutes. This figure is higher than what was assumed in the past. The plan is to test this claim at a level of significance …
6. ### statistics

A random sample of size 81 is taken from a large population, measuring the time it takes to complete a driverâ€™s license examination. The sample mean was found to be 43 minutes, and the sample standard deviation 5.71 minutes. Construct …
7. ### Statistics

A hospital claims that the mean waiting time at its emergency room is 25 minutes. A random sample of 16 patients produced a mean wait time of 27.5 minutes with a standard deviation of 4.8 minutes. Use the 1% level of significance to …
8. ### statistics

Waiting times at a doctor office are normally distributed with a mean of 35 minutes, and a standard deviation of 10 minutes. What is the chance a patient would have to wait over 50 minutes?
9. ### statistics

Waiting times at a doctor office are normally distributed with a mean of 35 minutes, and a standard deviation of 10 minutes. 25% of the patients have to wait less than how many minutes?
10. ### statistics

Use the given information to find the minimum sample size required to estimate an unknown population mean μ. How many commuters must be randomly selected to estimate the mean driving time of Chicago commuters?

More Similar Questions