At their​ inauguration, the ages of the first six​ (out of a current number of​ 45) presidents of a certain country were 55,64,61,65,64 and 53.Find the standard deviation of the ages at inauguration of the first six presidents.

Below are the times ( in days) it takes for a sample of 6 customers from Ivan's computer store to pay their invoices  21,29,36,28,40,32 find the standard deviation of this sample of times. Round your answer to two decimal places.

The mean or average number of days for someone age 12 and older in the US to smoke weed (if they smoke it at all) is 117.72 days per year.  The standard deviation is 131.60. What was the NORMAL number of days per year to smoke weed?

On a nationwide math test, the mean was 57 and the standard deviation was 4. If Roberto scored 90, what was his z-score?

Find the standard deviation of 62,65,80,81,97

Skye High School has a total of 500 graduates.  The mean SAT score of Skye High School graduates is 947 with a standard deviation of 205.  To get into a premier college, a student must score 1000 or more.  If 60 students are selected at random, how many graduates can Skye High School expect to get into a premier college?

Create a sample of ten numbers that have a mean of 3000. Demonstrate the concept of N-1 degrees of freedom used when calculating standard Deviation.

Of the 200 American film enthusiasts, the average age is: 30 years, while the standard deviation is 5 (five) years. Question  What is the age limit for American film fans who are classified in the 12% of the film fans group?

The data below represents the total number of points each hockey team in the NHL Eastern conference are in this past hockey season. Find the standard deviation. Round to the nearest tenth {52,66,84,88,93,100,101,117}

What is the population standard deviation for the numbers: 75, 83, 96, 100, 121 and 125