Answer:
![\boxed{ \bold{ \huge{ \boxed{ \bold{ \sf{25.75}}}}}}](https://img.qammunity.org/2021/formulas/mathematics/college/5kwkl98rkmmzlfhxls37ylepjlzex4d65z.png)
Explanation:
Given data : 20 , 25 , 28 , 30
Σx ( sum of all the items ) = 20 + 25 + 28 + 30 = 103
N ( total number of items ) = 4
Finding the mean
To find mean of the given data , divide the sum of all the items by the number of items.
![\boxed{ \sf{mean = (sum \: of \: all \: the \: items)/(the \: number \: of \: items)}}](https://img.qammunity.org/2021/formulas/mathematics/college/dc14j6eq6vy3utnrb41kfu9m3wjvh4w5me.png)
![\longrightarrow{ \sf{ (103)/(4)}}](https://img.qammunity.org/2021/formulas/mathematics/college/zw6s9r5kzzziojvo2wminhz77usl5p06de.png)
![\longrightarrow{ \sf{25.75}}](https://img.qammunity.org/2021/formulas/mathematics/college/iq8xahrsu2pm6bmzpk4w6bcz7bnhyez536.png)
Hope I helped!
Best regards! :D