Students - Project Maths - Learning and teaching for the 21st Century - Student Activity Stem and Leaf. Use in connection with the Stem and Leaf Interactive File

Mean and Standard Deviation Interactive Quiz

How many students are in the class?
1. 30
2. 7
What is the mid Interval value for the interval 6-8?
1. 3
2. 7
In the (Mid Interval - Mean) column in the table, is it true values less than the mean will give a negative value for the (Mid Interval -Mean) column?
1. Yes
2. 7
After the (Mid Interval - Mean) has been squared must we multiply it by the frequency, true or false?
1. False
2. True
Which of the following is the formula for standard deviation?
Reset the table and run the arrows again. Now if the number of people in the Interval 12-14 increased by 4, would the mean increase?
1. No
2. Yes
If the number of people in the interval 0-2 increased by 4, would it have the same effect as the interval 12-14 increasing by 4?
1. No
2. Yes
If you remove all of the students in the 4-6 interval, what effect will it have on the Standard Deviation?
1. It increases
2. It decreases
Now click the Reset button on the table, and fix it so that all 30 students are in the 6-8 interval, what is the standard deviation?
1. 30
2. 0
If all the students were in the range 12-14, then the Standard Deviation would be 0?
1. True
2. False