I've this much done, but haven't been able to find the quartile. Can you help? And tell me if I have gotten the mean, median, range, and mode right?

Math Test Scores

Stem| Leaf
5 | 1 3 5 9
6 | 1 6 9
7 | 4 6
8 | 0 1 2 4 4 4 9
9 | 2 2 3 6

Range: 45
Mean: 76.4
Median: 80.5
Mode: 84

Is all the above right? And how can I find the quartile?

I'm getting 76.05 for the mean. Check your calculation again.

Then, there are 4 types of quartile...
First quartile, second quartile (also mean), third quartile, and interquartile range.