If the mean is and the standard deviation is , which of the following is NOT within two standard deviations?

The formula for standard deviation is the following:

.

Where,

,

,

.

Five students took a test and recieved the following grades: , , , , . What is the standard deviation of the test grades to the nearest decimal place?

Standard Deviation can be calculated from what statistical term?

The ages of the students at Rosa Parks High School are normally distributed with a mean of 15.5 and a standard deviation of 0.6 years.

What is the proportion of students that are older than 16.2 years old?

The ages of the students at Central Universityl are normally distributed with a mean of 23.5 and a standard deviation of 2.5 years.

What is the proportion of students that are younger than 18.5 years old?

Find the standard deviation of the following set of numbers:

Ibram was paid $5000 for editing a 2200-page encyclopedia. What was his rate earned per page?

On 3 exams, Willow has an average score of 95 points. Her lowest score was an 90. If this score is dropped, what is her new average?

The mean of the following numbers is 13. Solve for x.

18, 15, 10, 8, x

In a normal distribution, what percentage is covered within one standard deviation?