TG EAMCET 3 May 2025 Shift 2 Paper

Step 1: List all values and probabilities
We have X taking the values 2,3,5,7, and 12 . Their probabilities are 3k,k,k,2k, and k.
Step 2: Make a table with useful information

Step 3: Find value of k
Add up all probabilities:
3k+k+k+2k+k=8k
Set equal to 1 :
8k=1
So, k=‌

1

8

Step 4: Find the mean and expected value of x2
∑pixi=40k
∑pixi2=288k
Step 5: Write the formula for standard deviation
SD=√∑pixi2−(∑pixi)2

Step 6: Substitute the values and solve
SD=√288k−(40k)2=√‌

288

8

−(5)2=√36−25=√11