If the scores of 3 students in a test are 5,6 and 7. Find the standard deviation of their scores.

0.82

Step-by-step explanation:

Step 1: (Calculating mean)

=>

=>

=> Mean = 6

Step 2:

=> (5-6)² = (-1)² = 1

=> (6-6)² = (0)² = 0

=> (7-6)² = (1)² = 1

Step 3: (Adding all values calculated in step 2)

=> 1+ 0 + 1 = 2

Step 4: (Dividing the result in step 3 by no. of observations)

=> 2/3 = 0.67

Step 5: (Get square root to calculate the deviation.)

=> = 0.82

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus