Answer:
![(11)/(18)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xpio9740pri2tvut3vjirr42w9fe620k3b.png)
Explanation:
From the given table , the total number 9th grades students gave math test =
![8+12+30+25+15=90](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a8km72j0tz2112nlf9bo0tvo5eix6krlbt.png)
The number of 9th grades students got score between 21 and 40 =
![30+25=55](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ub409thh3vzw02czpk7nr38e7jc4ruyfss.png)
Now, If a student is picked at random, the probability that his or her score is between 21 and 40 is is given by :-
![(55)/(90)=(11)/(18)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5k3ase9hoh4lyhavttz65vzm0l7yn22vif.png)
Hence, the probability that his or her score is between 21 and 40 is
![(11)/(18)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xpio9740pri2tvut3vjirr42w9fe620k3b.png)